Green’s Dictionary of Slang

up n.1

1. an excited mood, a feeling of stimulation, intoxication (cf. down n.1 ).

[UK]F.D. Sharpe Sharpe of the Flying Squad 158: They regard it as a business, taking arrests as a little ‘down,’ and a good haul as a nice ‘up.’.
[UK]K. Sampson Powder 334: He was loving every little bit of the adventure, and found himself on a permanent Up.

2. a prospective purchaser in a store [? they pick things up].

[US]Berrey & Van den Bark Amer. Thes. Sl.
[US]N.Y. Times 1 May 62: The hottest salesman who ever turned a looker into an up [OED].
[US]G.P. Pelecanos Firing Offense 43: At one point, when I moved to take an up, he stepped in front of me and threw an elbow into my stomach, keeping a wide smile plastered on his face as he greeted the customers.

3. (UK black) congratulations, praise; recognition.

[UK]T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Ups - praise, compliments, recognition.

In phrases

have the ups (v.) [abbr. of SE upper hand]

(US black) to have an advantage over.

[US]Mezzrow & Wolfe Really the Blues 217: You sure got the ups on us pigeons.
in two ups (adv.)

(Aus.) very quickly.

[Aus]T. Wood Cobbers 25: He said we’d be there in two ups.
[Aus]Baker Popular Dict. Aus. Sl. 79: Two ups, in, in a brief space of time.
[Aus]D. Ireland Glass Canoe (1982) 142: In two ups, he was drinking with four of the biggest blacks you’ve ever seen.