Synonyms for guard

noun

off one's guard

on one's guard

verb

1. To protect

   secure, shield, safeguard; see defend 1, 2.

2. To watch over

   watch, observe, superintend, stand sentinel, patrol, picket, police, look out, look after, see after, supervise, tend, keep in view, keep an eye on, keep under surveillance, attend, overlook, keep a prisoner, hold in custody, stand over, babysit, care for, keep vigil, look to, see to, chaperone, shepherd, oversee, keep a weather eye*, ride herd on*, keep tabs on*, be a father to*.

   Antonyms disregard, neglect*, forsake.