to declare or admit (something) openly or freely
to declare (something) falsely; to claim or pretend (something)
to confess one's faith in or allegiance to (e.g. a religion)
to receive (somebody) formally into a religious community
archaic or humorous to be a professor of (an academic discipline)
to make a profession or avowal
[Latin professus, past part. of profitēri to profess, confess, from pro-1 + fatēri to acknowledge; (sense 3) Middle English profes (adj) having professed one's vows, via French from Latin professus]