WordNet (r) 3.0 (2006):

give thanks
    v 1: express gratitude or show appreciation to [syn: thank,
         give thanks]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "give thanks":
   acknowledge, beseech, bless, commune with God, credit, give credit,
   implore, invoke, make acknowledgments of, make supplication,
   offer a prayer, offer thanks, petition, pray, pray over,
   recite the rosary, recognize, render credit, render thanks,
   return thanks, say grace, supplicate, thank