From Longman Dictionary of Contemporary Englishup to somethingup to somethinga) INCLUDEas much or as many as a certain amount or number but not more The Olympic Stadium will hold up to 80,000 spectators. a process that can take anything up to ten days b) UNTIL (also up till) for the whole of a period until a certain time or date She continued to care for her father up to the time of his death. We’ve kept our meetings secret up to now. c) GOOD ENOUGH[in questions and negatives] clever, good, or well enough to do something I’m afraid Tim just isn’t up to the job (=he does not have the necessary ability). You don’t need to go back to school if you don’t feel up to it.up to doing something He’s not really up to seeing any visitors. d) GOOD ENOUGHif something is up to a particular standard, it is good enough to reach that standard I didn’t think last night’s performance was up to her usual standard. e) DO spoken doing something secret or something that you should not be doing The children are very quiet. I wonder what they’re up to. He knew Bailey was up to something. But what? I always suspected that he was up to no good (=doing something bad). → up
Examples from the Corpus
up to no good• I think Ken's up to no good.• They were organizing, they were.. up to no good.• When the political right starts appealing to liberty, it is frequently up to no good. 