ballocks (!) Noun. 1. The testicles. A variation on "bollocks". S.E. from 1200s, slang from mid 1800s. Cf. "bollocks". 
2. Rubbish, nonsense. 
Exclam. An exclamation of annoyance, disbelief or disagreement.

 balloon knot Noun. The anus. From its appearance.

balls (!) Noun. 1. Testicles. Usually in plural. 
2. Courage, in for example, "She hasn"t got the balls to tell him the truth." 
3. Rubbish, nonsense. 
Exclam. Expressing annoyance.

 ballsed-up Adj. Ruined, in a mess.

 balls (something) up Verb. To make a mess of a situation. E.g."I couldn"t believe I ballsed up my driving test by making exactly the same mistake as the previous six times."

 balls to the wall Phrs. Quickly.

 balls-up Noun. A mess up, a "cock-up". E.g."I"ve made a right balls-up of my exams." 
Verb. To make a mess of a situation.

balm Noun. A bread bun or roll. Common mispelling of barm. Cf. "barmcake".

 balmy Adj. Insane, crazy. A derivative of the earlier "barmy."

baloney Noun. Nonsense. Also spelt boloney. [Orig. U.S.]

baltic Adj. Very cold, with respect to the weather or air temperature. [Orig. U.S.]

bam Noun. A foolish and objectionable person. Abbreviated form of "bampot". Derog. [Scottish use]

bampot Noun. A foolish and objectionable person. Derog. Cf. "bam" and "bamstick". [Scottish use]

bamstick Noun. A foolish and objectionable person. Derog. Cf. "bam" and "bampot". [Scottish use]

 banana Noun. A penis

. bananas Adj. Insane, mad, hysterical. [Orig. U.S.]

 bang Verb. 1. To copulate. A particularly aggressive term. 
2. To put or place, the implication being with nonchalence. E.g."I"ll bang those in an envelope and send them off first post in the morning." 
Noun. An act of copulation.

banger Noun. 1. A sausage. The English meal of sausages and mashed potato is traditionally called bangers and mash.
2. A delapidated car. 
3. A small firework that is explosively loud but visually unstimulating.

 banging Noun. Sexual intercourse.
Adj. Exciting, energetic, wonderful, excellent. Often heard pronounced bangin".

bang on Adj./Adv. Exactly, correct. {Informal}

 bang on about (something) Vrb phrs. To talk incessantly and uninterestingly, to nag. E.g."You"re not going to change my mind by banging on about it!"

bang one out Vrb phrs. To masturbate. E.g."Steve watched Bay Watch on TV and then banged one out before his mum came home."

 bang out of order Phrs. Totally unacceptable.

bang-tidy Adj. Sexually attractive.

 bang to rights Phrs. Caught red-handed. Police/criminal vernacular often heard used jocularly.

 bang (someone) up Verb. 1. To put (someone) in prison. {Informal}. 
2. To make (someone) pregnant.

 banjax Verb. To ruin. [Mainly Irish use.]

banjaxed Adj. 1. Ruined, defeated. Originally Anglo-Irish use, popularized by the UK radio/TV presenter Terry Wogan with his book of the same name. 
2. Drunk, by extension of meaning 1.

 banjo

Verb. To hit or punch. [Scottish use]
Noun. 1. A sandwich, particularly one that contains sauce type condiment or other runny ingredient that may spill onto one"s clothes, for example egg banjo (fried egg sandwich).
2. A shovel. [Orig. Aust.]

banjo"d Adj. Drunk, intoxicated.

 banjo string Noun. The frenulum of the penis.

 banko Noun. Abb. of bank holiday (a national holiday).

 baps Noun. Breasts. E.g."Look at the baps on her!"

bar Noun. One pound sterling.

 barbie Noun. Abb. of barbecue. [Orig. Aust.]

 barbs Noun. Abb. of barbituates.

 Barclay"s (Bank) Noun. An act of masturbation. From the rhyming slang for "wank".

 barcode Noun. A supporter of the Newcastle United football club. From their team kit being designed around black and white vertical stripes, like a barcode.

 bare Adj. A lot of, significant amount. E.g."It"s just bare hype, the film"s just famous faces and no plot." [London use]
Adv. Significantly. [London use]

 barf Verb. To vomit, probably onomatapoeic in origin. E.g."He"s feeling woozy, I think he"s gonna barf his dinner up." [Orig. U.S. 1940/50s]

barking Adj. Insane, crazy. Short for barking mad.

 barking spider Noun. The anus.

 barmcake Noun. 1. A lighthearted term for a fool or idiot. 
2. A bread bun. Also barm cake. [North-west use]

barmpot Noun. A silly person. A lighted-hearted expression.

barmy Adj. Mad, crazy, insane. Cf. "balmy". [1600s]

barnet Noun. Hair. From the Cockney rhyming slang barnet fair. [Mid 1800s]

 barney Noun. An argument. [Late 1800s] {Informal}

barney (rubble) Adj. Trouble. Rhyming slang. [1960s]

 barry Adj. Good, nice. [Edinburgh use]

Barry White * Noun. 1. Rubbish, nonsense. 
2. An act of defecation. 
* Both uses are rhyming slang on "shite" (shit). See "shite". Barry White, U.S. soul singer who came to the fore in the 1970s.

barse Noun. The perineum. From the area between the balls and the arse.

 bar steward Noun. A pun on "bastard".

 base over apex Phrs. Head over heels, upside down. E.g."His front wheel hit a rock on the road and he went base over apex."

 bash Noun. 1. An event, a party. E.g."I"m having a bash at a club for my birthday."
2. An attempt. E.g."Try having a bash at the next question if you can"t answer the first."

bash the bishop Verb. To masturbate. Derived from the similarity of the head of the penis with a bishop"s mitre. E.g."It"s a myth that constantly bashing the bishop makes you blind."

 basket Noun. A euphemism for "bastard".

 basket case Noun. An emotionally unstable person, a dysfunctional person, a completely useless person. Originally an amputee, especially a soldier, who had lost all four limbs, coined during the First World War.

 bastard (!) Noun. 1. A contemptible person. Derived from the original meaning, an illegitimate person, when to be born out of wedlock was viewed as objectionable. 
2. A pitiable person. E.g."That poor bastard never stood a chance once the avalanche started." 
Adj. Used as an negative intensifier. E.g."My bastard car wont start again!" 
Exclam. Exclamation of anger.

 bastarding Adj. An intensifier. E.g."I"m sorry for being late, I missed the bastarding bus again!"

bat for both sides Vrb phrs. To be bisexual.

 bat for the other team Vrb phrs. 1. To be homosexual. E.g."He wont be interested in your sister, he bats for the other team."
2. To be of a different sexual persuasion.

 bat for the opposition Vrb phrs. To be homosexual. 
2. To be of a different sexual persuasion.

bathers Noun. Swimming/bathing costume. [Orig. Aust./N.Z.] {Informal}

 bat in the cave Noun. A globule or lump of nasal mucus when visible up a nostril.

 bat on a sticky wicket Vrb phrs. To put oneself in a difficult and unfavourable position.

 battered Adj. Very intoxicated by drink or drugs.

 battery operated boyfriend Noun. A vibrator, sex toy. Cf. "bob".

battle cruiser Noun. A pub, bar. From rhyming slang for "boozer". See "boozer" (noun 1).