up to something

up to something

Actively engaging in mischief or preparing to do something nefarious, usually in clandestine way. That guy over there keeps snooping around the front of the store—I think he's up to something. Why won't you tell me who you were on the phone with? Are you up to something?
See also: something, up

up to something


1 (also up to doing something) physically or mentally capable of something: She didn’t feel up to going to work today.At my age, I just don’t think I’m up to climbing 200 steps.He’s just not up to the job, I’m afraid.
2 (spoken) doing something, especially something bad: What’s she up to?We used to get up to all sorts of things when we were that age.
See also: something, up