"OK"
Meanings: (1) yes (to show agreement--often reluctant agreement); (2) neither good nor bad; so-so; (3) in satisfactory condition; well; (4) approve (verb)
Example:
A: "How was the buffing machine?"
B: "OK, but I've seen better ones."
Last week's idioms:
had('d) better
if I had my druthers
jump all over (someone)
keep an eye on
lend (someone) a hand