Green’s Dictionary of Slang

watch v.

SE in slang uses

In compounds

watchpot (n.) [they watch the cooking pot]

[late 19C–1910s] (Irish) one who hangs around at mealtimes in the hope of being offered a meal.

watch queen (n.) [SE watch + -queen sfx (2)]

[1970s+] a male homosexual voyeur.

In phrases

watch it (v.)

[late 19C+] to look out, to be careful; esp. in imper. watch it! used as a warning or a threat.

watch one’s ass (v.) [SE watch + ass n. (2)] [1960s+] (orig. US)

to take care, to take note, to be warned; usu. as watch your ass.

watch one’s back (v.)

[1950s+] to take care of oneself.

watch oneself (v.)

[1950s+] to take care; esp. as an imper. when the implication is of a threat from the speaker.

watch one’s lip (v.) (also ...mouth, ...tongue) [lip n.1 (1a)/mouth n. (3)/SE tongue]

[1950s+] to mind one’s manners, to talk politely; also as imper.

watch someone’s back (v.) (also take...) [1950s+]

1. to look after or protect someone else.

2. to take care of someone else.

watch someone’s waters (v.) [SE hold one’s water, to delay urination]

[18C–early 19C] to keep a close watch on someone’s actions.

watch the ant races (v.) [the image of having collapsed on the floor]

[1970s+] to be excessively drunk.

watch (the) submarines (race) (v.) (also watch submarine races)

[1960s+] (US) to indulge in sexual by-play; thus submarine watching n.

In exclamations

watch my dust! [the SE dust of departure; note dust v.2 (1)]

[1910s+] (US) see me go!

watch your hip! [euph. hip, the buttocks, the backside]

[1950s+] (W.I.) watch your manners!