come the acid
To be unpleasant or offensive, usually due to speaking in a caustic or sarcastic manner. Often followed by "with (someone)." Don't come the acid with me, son, or I'll knock you upside the head. I try to avoid her whenever I can, for she's far too quick to come the acid.
put the acid on (someone)
To beg, importune, or proposition (someone) for something, such as a money loan, a favor (sexual or otherwise), or information. Primarily heard in Australia, New Zealand. My no-account brother-in-law is always putting the acid on for a money loan—which, I'll add, he has never once paid back. It's like he's surprised when women in a random bar don't all come up putting the acid on him.
be on acid
To be under the influence of lysergic acid diethylamide (LSD), a powerful psychedelic drug commonly known as "acid." A lot of my friends like being on acid, but it just makes me feel really tense and paranoid.
on acid
Under the influence of lysergic acid diethylamide (LSD), a powerful psychedelic drug commonly known as "acid." The man was reportedly on acid when claimed he could fly and tried to jump off the building.
acid test
A conclusive test. The phrase comes from the 19th-century practice of testing metals in nitric acid to determine if they contained gold. Restructuring the organization will be the acid test that determines whether or not it can survive the sudden downturn in the economy.