Green’s Dictionary of Slang

shag v.1

also sheg
[? SE shake, hence shake v.]

1. [late 17C+] to have sexual intercourse; thus shag around, to lead a promiscuous sex-life.

2. [late 19C+] used as a semi-euph. for fuck v. in various non-copulatory uses.

3. [20C+] to masturbate.

4. [1950s–60s] to assault, to beat up.

5. [2000s] to cheat.

In derivatives

shagability (n.)

[1990s+] one’s sex appeal.

shaggable (adj.)

[1990s+] sexy, lit. (potentially) available for seduction.

shagtastic (adj.) [-tastic sfx]

[2000s] extremely sexually alluring.

In compounds

shag-happy (adj.) [-happy sfx]

[2000s] keen on sexual intercourse.

shag-nasty (adj.)

1. [mid-19C+] a general pej. name for any unpopular man.

2. [1980s+] (N.Z.) used affectionately.

3. [2000s] (Aus.) something unpleasant.

In phrases

shag ass (v.) [SE shake/shag v.2 (6) + ass n. (4)] [1950s+] (US)

1. to work hard, to move fast, to expend effort and energy.

2. (also shag one’s ass) to depart or leave hurriedly.

shagged off (adj.)

[1990s+] fed up, infuriated.

shagged (out) (adj.) [fig. use of sense 2 above, i.e. euph. for fucked adj.1 ]

1. [1930s+] exhausted.

2. [1940s+] broken, out of order.

shag out (v.)

1. [1950s] to exhaust.

2. [1970s] to eject.

In exclamations

shag me!

[1980s+] (N.Z.) an excl. of astonishment and/or resignation; a semi-euph. for fuck me! excl.