'up to' definitions:

Definition of 'up to'

(from WordNet)
adjective
Busy or occupied with; "what have you been up to?"; "up to no good"
adjective
Having the requisite qualities for; "equal to the task"; "the work isn't up to the standard I require" [syn: adequate to(p), capable, equal to(p), up to(p)]

Synonyms of 'up to'

From: Moby Thesaurus