Rabbit, to (rhyming): to talk
The missing rhyming component is "rabbit and pork."
Source: SL

Rack, The: a path in Sefton Park for courting couples
Source: MM

Rack off: a dismissive remark, meaning to go and disappear, to get lost. A variant of nick off, fuck off.
Source: DS

Radar Gear: spectacles
Source: LS3

Raddled: lost, bewildered
Source: LS2

Raggety kecks: worn-out knickers or tattered drawers; the term often is used to refer to a "slummy" or slum-dweller. The remote source is probably the Ragged Schools run for severely impovershed slum children.
Sources: LS2, Moloney

Ragman. De Ragman, or raggie. The old-clothes man. A junkman was often called a rag and bone man. Some remember that he would trade goldfish for old clothing.
Sources: LS1, Schur

Ragtag and bobtail: the poorest of the poor
Source:  GS

rag tatter(obsolete): person who pays or trades for rags
Source: GU

Railings: the teeth
Source: LS3

railway bogies: railway police
Source: LI30

randy sod: an amorous person; a lady killer
Source: LS2

Rantan. Lissen to his rantan: He is knocking loudly.In Lancashire, referred to a loud knock at the outer door, or a noisy disturbance of any sort.
Source: LS1

rap: a half penny, formerly applied to an Irish half-penny.  Hence "I don't give a rap...."

rat catchers: R.C.s Roman Catholics
Source: LS2

Rat-arsed, to get: to get very drunk
Source: SL

rat-trap cars: a new car which is left in an area where there have been many car thefts. The car is rigged so that, when stolen, the engine cuts off after a few yards and all the doors lock, trapping the "rats" inside, who are now subject to arrest.
Source: LS4

Rattler: a tram or street-car, or (plural) the stairs to them, or any stairs.
Sources: LS1,LS2

Rave, to: to go partying, as in to be out raving
Source: SL

Raver: party-goer
Source: ANS

razz, going for a : to take a joy ride in a stolen car
Source: LS4

Readies: money
Source: LS3

real bother, to be in: to be experiencing unusual difficulty or inconvenience because of something
Source: SL

Ream: beautiful
Source: LS3

reasty(sometimes spelled reesty): rancid. In Lancashire, reesty means rusted or discolored, as is said of strong or rancid bacon.
Sources: SL, OED, GLD

Red biddy: cheap red wine. It can also refer to a potent mix of port and meths.
Sources: LS1, Moloney

red nose, a: a Liverpool football fan
Source: SL

Red raddle: a hard block of red powder used for cleaning and colouring window-sills, doorsteps and brickwork, and in some cases a cheap substitute for rouge.
Sources: LS2, Moloney

red reins: on a funeral horse, this would be taken as an assertion that the deceased had been murdered.
Source: LWAS

Red Gurnet: a large spiny headed fish, known for the grunting noises it makes when taken.
Sources: OED, SL

Red meg: a mythical coin of no value whatever
It ain't worth a red meg: it is completely worthless.  Also see "meg" on this list.
Source: LS2

Red Hot John: the term comes from the name of a Salvation Army Officer in Bootle who was known for his reformist zeal. It can refer to anyone who is delivering a ferocious moral rebuke.
Source: LS2

red-blooded all-American fullback: derisory term for a braggart; a self-styled hero.
Source: LS2

Redband: a trusted prisoner (or "trustee"), who wears a red arm-band signifying that.
Source: LS4

redneck: Catholic term for a Protestant
Source: GTH
Redneck: a Catholic
Source: LS2
Obviously, it depends who is talking.

Redskin: a trouble-maker.
Source: LS1

Regulo: proprietary name of a thermostatic control for a domestic gas oven.
Source: OED

Rellie: relative. Rellos is frequently the plural.
Source: SL

Rent book: bail money
Source: LS1

Rent Boys: male prostitutes
Source: LS4

Rentagob, a: a man who tends to "run at the mouth.'
Source: Moloney

Rentfeller. The rent collector.
Source: LS1

repping: the job of being a commercial salesperson
Source: SI

rhubarb crumble: treat served at the school canteen
Source: SL

Rhubarb Vaselino: term for a young man who preens himself excessively
Source: LS2

ribble: commuter bus
Source: PM

Ring the bell: to make a woman pregnant. A father of a large family is said to ring the bell every time. The allusion is to the strength games at Fairs.
Source: LS2

Ringer: stolen car( or a horse, or a necklace, etc.) disguised so as to avoid detection
Source: LS4, Moloney

Rip( or to let rip): to pass wind with unseemly vigour.
Source: LS2, Moloney

Riviera, der: The Isle of Man
Source: LS3

roach: a small freshwater fish of the carp family, common in the rivers of Northern Europe
Source: OED

roach end: improvised mouthpiece for a rolled joint, or "spliff," made from the cardboard casing of cigarette papers, or "skins."
Source: LS4

road through: bowel movement
Source: LS1

roady: mixed.  In Lancashire it is used to describe bacon which has alternate layers of fat and lean.
Source: GLD.  See "rodey bacon" on this list.

Roasty(sometimes spelled roastie): roast potato, but it can also mean a roast.
Source: SL.

Robin's Breakfast: a child's Christmas breakfast, prepared in particular for needy children
Source: DBAPOI

Robins: a brand of cigarettes popular during the last World War
Source: SL

Rock: rock candy
Source: SL

Rocky Racoon (rhyming): the moon
Source: LS3

Rodey bacon: Streaky bacon.  See "roady" on this list.
Source: LS1

rofe, a: four pounds
Source: LS1, LS3

Roger Bollocks:a generic name, often used when addressing someone confrontationally
Source: SI

Roller (or roll boy): a very pious person.
Spiegl thinks this may be derived from the line "When the roll is called up yonder I'll be there," but the derisive phrase "holy rollers," and their reputation for rolling in the aisles,  might be the origin.
Source: LS2

rollies:  hand rolled cigarettes
Sources: LS4, SL

Rollin' in ther shit: thoroughly drunk
Source: LS2

Rollin' yer own: incest
Source: LS4

rope, a(obsolete): an inexpensive and tawdry place for drunken sailors to spend the night, A rope would be stretched from one wall to another, and the sailors would drape themselves over it. It was also called a "tuppenny kip."  The term "lascar rope" for cheap overnight lodgings is the source here.
Source: UF

roped up, to be: to have stitches put in a wound
Source: LS3

Ropey: of poor quality
Source: LS2

Rose of Tralee: sarcastic name given to an old and slovenly woman.
Source: LS2

Rota do Bacalhau(Portuguese): the codfish route, sailed by the Portuguese and others for well over four hundred years.
Source: SL

Rotten: very drunk
Source: LS2

Rounders: a children's game, supposedly a forerunner of baseball, via softball.
Source: SL

Rounds. She give im de rounds uv de kitchen. They had a domestic altercation.
Source: LS1

Rowdy do: extremely informal, and some times spontaneous, party
Shaw says that "rowdy" can mean low, but not necessarily noisy.
Source: Shaw II

Rozzer: a police constable. Norder thinks that the term may come from the Romany word for strong man: "roozolus."
Source: LS2, LS4

Rube: a fairground or circus attendant
Source: LS2

Ruck: animal excrement. Mind dat ruck on der parapet: beware of the (dog) mess on the pavement.
Source: LS1

rumbled, to be:  to be informed on or exposed
Source: SL

Rumpy Pumpy: sexual intercourse
Source: LS3

run-out, giving a: in soccer, easing a sidelined player back into a team
Source: GTH

rushin': injecting narcotics
Source: LS4

Ruthless Rufus: Whozit, whatsizname, applied specifically to a person in a position to administer punishment, such as a headmaster or a magistrate.
Source: LS2