Green’s Dictionary of Slang

knocker n.1

[knock v.]

1. in sexual contexts.

(a) [17C] a promiscuous man, a whoremonger.

(b) [late 17C+] the (head of the) penis.

2. in pl., as a part of the body.

(a) [late 19C+] the testicles [they ‘knock together’ but note knackers n.].

(b) [1930s+] (orig. US) the female breasts; occas. in sing.

3. a physically or socially superior individual.

(a) [17C–19C] an outstandingly attractive person or thing.

(b) [late 19C+] (US, also k’nocka) the top person, the person in authority, often in comb., e.g. head knocker under head n., top knocker [their ‘striking’ appearance].

(c) [1900s] (Aus.) the ideal, the best way.

4. a form of hair dressing seen as resembling a door-knocker.

(a) ‘a Man’s hair tied behind in a Club’ (Grose, c.1786).

(b) [early–mid-19C] a form of pendant to a wig, similar to a pigtail.

(c) [19C] a small curl worn flat on the temples, a fashionable hairstyle at that time [abbr. door-knocker n. (2)].

5. in context of communication.

(a) [late 19C+] (US Und.) an informer or complainant.

(b) [late 19C+] (orig. US) a critic, esp. one who relishes making negative comments.

(c) [1900s–50s] a criticism; negative comments; also as the knockers.

6. [1920s–30s] (UK tramp) an arrest.

7. [1920s+] in UK Und. uses.

(a) a gambler or prisoner who refuses to pay their debts (which cannot be enforced legally in the UK).

(b) one who passes bad cheques or gains goods on credit — and fails to pay the bill.

(c) (UK Und.) a scrounger.

8. see hard-hitter n.

9. see knocko n.

SE in slang uses

In compounds

knocker-face (n.) (also knocker-head) [reminiscent of an old-fashioned door knocker]

[late 19C–1920s] an ugly face, or the person who ‘owns’ it.

knocker-gear (n.)

low-value goods that are sold door-to-door, mainly as a pretext for gaining an introduction to the owner, who may thus be defrauded of heirlooms and/or valuables.

knocker-worker (n.)

[20C+] a door-to-door pedlar.

In phrases

dressed up to the knocker

[19C] dressed in one’s best clothes.

full to the knocker (adj.)

[2000s] (N.Z.) completely drunk.

live up to the knocker (v.) (also live up to the door)

[mid-19C–1900s] to live up to one’s means.

on the knocker

1. [mid-19C+] (UK Und., also on the knock) touring houses, ostensibly to buy or sell goods, but spec. to trick or bully people into selling heirlooms, antiques etc. for minimal prices; thus the knocker (game), working as a fraudulent door-to-door salesman.

2. [1930s+] (Aus., also on the knob, on the knuckle) at once, on demand, esp. of cash payments, exactly.

3. [1940s] working as a door-to-door salesman.

overstep the knocker (v.)

[1910s] (Aus.) to drink to excess.

up to the knocker [sense 3a or fig. use of SE (door) knocker]

1. [mid-19C–1910s] capable, up to a task.

2. [mid-19C+] fashionably dressed or over–dressed.

3. [late 19C] in prime condition; enjoying oneself.

4. [late 19C] completely.