Synonyms for Subscribe (same or very similar meaning)
WordNet sense 1 (pay (an amount of money) as a contribution to a charity or service, especially at regular intervals):
pledgeWordNet sense 2 (receive or obtain by regular payment):
take, subscribe toWordNet sense 3 (mark with one's signature; write one's name (on)):
signWordNet sense 4 (adopt as a belief):
supportFrom the ODE community, based on WordNetadd/edit