Agree, consent, accede, assent, concur all suggest complying with the idea, sentiment, or action of someone. Agree, the general term, suggests compliance in response to any degree of persuasion or opposition: to agree to go; to agree to a meeting, to a wish, request, demand, ultimatum.
Consent, applying to rather important matters, conveys an active and positive idea; it implies making a definite decision to comply with someone's expressed wish: to consent to become engaged.
Accede, a more formal word, also applies to important matters and implies a degree of yielding to conditions: to accede to terms.
Assent conveys a more passive idea; it suggests agreeing intellectually or verbally with someone's assertion, request, etc.: to assent to a speaker's theory, to a proposed arrangement.
To concur is to show accord in matters of opinion, as of minds independently running along the same channels: to concur in a judgment about a painting. 5.