WordNet sense 1 (keep or maintain in unaltered condition; cause to remain or last):

continue, preserve, uphold, carry on, bear on

WordNet sense 2 (demand as being one's due or property; assert one's right or title to):

arrogate, claim, lay claim

WordNet sense 3 (stand up or offer resistance to somebody or something):

resist

WordNet sense 4 (become a participant; be involved in):

enter, participate