Green’s Dictionary of Slang

juggler n.

1. a fornicator, a womanizer [juggle v. (1)].

[UK]Shakespeare Henry IV Pt 2 II iv: Away, you bottle-ale rascal! you basket-hilt stale juggler, you!
[UK]Beaumont & Fletcher Wild-Goose-Chase III i: I hate him, And would be marryed sooner to a Monkey, Or to a Jack of Straw, than such a Juggler.

2. (prizefighting) a throw that takes down an opponent.

[UK]Pierce Egan’s Life in London 12 June 157/2: Smith hit with his right-hand, but missed, when the bear sent him down with a juggler.

3. someone who keeps many relationships going at the same time.

[US]E. De Roo Go, Man, Go! 83: Now I know why you didn’t want to tell Beano the truth [...] Same reason you don’t wanna be honest with me. You’re a juggler. You keep lots of balls in the air. That way you can reach out and grab what’s ever.

4. in drug uses [juggle v. (4)].

(a) (drugs) an addict who sells drugs to help finance their own addiction.

[US]Smith & Gay Heroin in Perspective (1972) 107: A juggler is considered to be doing well if he has enough money left over after a transaction for cab fare to where he buys the heroin. One informant defined a juggler as a ‘nonhustling dope fiend who is always messing the money up’.

(b) a street dealer, orig. of marijuana, latterly of crack cocaine.

[UK](con. 1981) A. Wheatle East of Acre Lane 139: He wet up dat Chinese Jamaican juggler, Clinton Wong.
[US]ONDCP Street Terms 13: Juggler — Teen-aged street dealer.

5. (US Und.) an expert at fraudulent manipulation of accounts [14C SE juggler, one who deceives by trickery; a trickster].

[US]E. Torres After Hours 105: Saso [...] is a juggler and a halfhandy.