Green’s Dictionary of Slang

1. (drugs) to consume pills or any drug that can be taken orally.

1961		Rigney & Smith Real Bohemia xx: The drugs are either inhaled, swallowed or injected [...] To take orally is to ‘drop it’.
1971		B. Moyers Listening to America 101: I was a real acid head, dropping acid every day.
1980		E. Folb Runnin’ Down Some Lines 174: I was at home, there was this party going on, and me and my old man dropped some acid.
1992		in R. Graef Living Dangerously 47: I can’t go out to a rave without dropping an E.
2000		N. Griffiths Grits 81: Christ, must-a dropped enough fuckin drugs t’fell-a fuckin ox like.
2004		R.G. Barrett Rosa Marie’s Baby (2013) [ebook] Snort a few lines of coke, drop a tab of acid and do a bit of crystal meth.
2006		C.W. Ford Deuce’s Wild 257: A group of kids who smoked dope and dropped acid gathered around him.
2015		P. Doyle (con. 1969-1973) Big Whatever 26: I dropped a mandy to ease the jingle-jangle.

2. to drink (beer).

1980		Spoonie G ‘Monster Jam’ 🎵 I drop a can of beer without a spill.
1996		(con. 1964-65) B. Thorpe Sex and Thugs and Rock ’n’ Roll 4: [S]houting her a few Scotches, which she dropped like a wharfie.