Synonyms for surprise

noun

1. A feeling of amazement

   astonishment, wonderment, shock; see wonder 1.

2. The cause of surprise, sense 1

   something unexpected, blow, sudden attack, unexpected good fortune, sudden misfortune, unawaited event, unsuspected plot.

take by surprise

verb

1. To amaze

   astonish, astound, amaze, bewilder, confound, shock, overwhelm, dumbfound, unsettle, stun, electrify, petrify, startle, stupefy, stagger, nonplus, take aback, cause wonder, strike with wonder, strike with awe, dazzle, daze, perplex, stagger one's belief, leave open-mouthed, leave aghast, make all agog, flabbergast*, floor*, bowl over*, jar*, flash upon one*, carry one off his feet*, jolt*, take one's breath away*, strike dumb*, make one's hair stand on end*, make one's head swim*, creep up on*, catch unaware*; see also confuse, frighten 1.

2. To take unaware

   take by surprise, catch one in the act of, burst in upon, startle, catch off-balance*, catch flat-footed*, catch one napping*, catch asleep*, nab*, pop in on*; see also sense 1.

surprise implies an affecting with wonder because of being unexpected, unusual, etc. I'm surprised at your concern; astonish implies a surprising with something that seems unbelievable to astonish with sleight of hand; amaze suggests an astonishing that causes bewilderment or confusion amazed at the sudden turn of events; astound suggests such a shocking surprise that one is left helpless to act or think I was astounded by the proposal; flabbergast is a colloquial term suggesting an astounding to the point of speechlessness