practice as a profession, teach, or claim to be knowledgeable about
confess one's faith in, or allegiance to
To make open declaration of, as of one's knowledge, belief, action, etc.; to avow or acknowledge; to confess publicly; to own or admit freely.
To set up a claim to; to make presence to; hence, to put on or present an appearance of.
To present to knowledge of, to proclaim one's self versed in; to make one's self a teacher or practitioner of, to set up as an authority respecting; to declare (one's self to be such); as, he professes surgery; to profess one's self a physician.
To take a profession upon one's self by a public declaration; to confess.