I have used the word "tweaking" for a couple of decades. When I was a kid that is what we call sneaking up on your friend an flicking their ear hard enough to make then jump about 5 feet off the ground. But I have just been using it to mean "making a small adjustment". However I found out the hard way when a friend started laughing at me that this is not the only slang use of the word. In addition to sometimes referring to masturbation (In Britain I think) and certain other sexual practices I found out it means freaking out on speed, and so on.
I usually tell them it's official as "making a small adjustment" since it was in the movie "You've Got Mail", but that barely stops most people from giggling at me (i.e. "tweeking out") about my mistake.