WordNet sense 1 (filled with the emotional impact of overwhelming surprise or shock):

amazed, astonished, astonied, astounded

WordNet sense 2 (taken unawares or suddenly and feeling wonder or astonishment):

surprised

WordNet sense 3 (knocked unconscious by a heavy blow):

out, kayoed, KO'd, knocked out

WordNet sense 4 (in a state of mental numbness especially as resulting from shock):

dazed, stupefied, stupid

WordNet sense 5 (mentally confused; unable to think with clarity or act intelligently):

confused