Green’s Dictionary of Slang

shark n.

1. in Und. uses.

(a) [late 16C+] (also sharker) a confidence trickster, a crooked gambler.

(b) [late 18C–1900s] a pickpocket.

2. [17C] a parasite, a hanger-on.

3. in senses of legalized extortion.

(a) [17C+] (also sharkie) a sharp operator, a crooked businessman; thus sharky adj.

(b) [late 18C–1910s] a custom house officer.

(c) [early–mid-19C] as the sharks, the press gang.

(d) [mid-19C+] a lawyer; also attrib.

(e) [1910s+] a supplier of private loans at maximum interest; a loan shark n.

(f) [1920s] (US) a pawnbroker.

(g) [1920s+] (US, also labor shark) an employment agent.

(h) [1930s] (US) a private detective.

4. in US campus uses.

(a) [mid-19C] one who deliberately misses a lesson or similar compulsory attendance; the act of choosing to miss such an attendance.

(b) [late 19C–1920s] a very intelligent or hard-working student; thus shark on stilts n., a brilliant student.

5. [late 19C] (US) an amoral, hedonistic individual.

6. in senses of expertise.

(a) [1910s+] (US) an expert, an authority.

(b) [1920s–40s] a womanizer.

(c) [1920s+] a pool shark

7. [1980s] (US black) a sharkskin suit.

8. [1990s+] (US prison) a dangerous, violent person.

9. a sardine.

In compounds

shark and taties (n.)

[1980s+] (N.Z.) fish and chips.

shark-bait (n.) (also shark-baiter)

[1910s+] (Aus.) a solitary swimmer swimming too far out at sea; thus shark-baiting n.; also used fig. .

shark biscuit (n.) [on model of SE dog biscuit] [1920s+] (Aus.)

1. a novice surfer.

2. the victim of a shark attack.

3. a bodyboard.

shark-hunter (n.)

[1920s] (US Und.) a thief who robs a drunk.

shark’s piss (n.)

[1900s] weak beer or other alcohol.

In phrases

harbour shark (n.)

[1990s+] (W.I.) a greedy person.

land shark (n.)

1. [17C] a ruffian, a thug.

2. [19C] a policeman.

3. [19C] a custom house officer.

4. [19C] a lawyer.

5. [19C] (US, also land-shark hog) a wild hog.

6. [mid-19C–1930s] a money-lender, a usurer.

7. a confidence trickster; a swindler.

8. in attrib. use of sense 7.

go upon the shark (v.)

to practise confidence trickery, to practise stealing.

pool shark (n.)

[late 19C+] (US) an expert pool player, esp. one who makes money by winning at pool.

shark week (n.)

[2010s] (US) the menstrual period.