Synonyms for Competent (same or very similar meaning)
WordNet sense 1 (legally qualified):
qualified
WordNet sense 2 (able to accomplish a purpose; functioning effectively):
efficient
WordNet sense 3 (have the skills and qualifications to do things well):
able, capable
WordNet sense 4 ((sometimes followed by `to') meeting the requirements especially of a task):
adequate
From the ODE community, based on WordNet
add/edit