"address with expressions of sympathetic pleasure," 1540s, from Latin congratulatus, past participle of congratulari "wish joy," from assimilated form of com "together, with" (see con-) + gratulari "give thanks, show joy," from gratus "agreeable" (from suffixed form of PIE root *gwere- (2) "to favor"). Related: Congratulated; congratulating; congratulable.
"feelings and expressions of joy, exultation, or gladness," late 14c., rejoising, verbal noun from rejoice (v.). Related: Rejoicingly. Rejoicement (1560s) seems not to have caught on.
"act of exulting, great gladness, triumphant delight," late 14c., exultacioun, from Old French exultacion "joyousness, exultation" and directly from Latin exultationem/exsultationem "a leaping for joy, exultation," noun of action from past-participle stem of exultare/exsultare (see exult). The notion is of leaping or dancing for joy. An Old English word for it was heahbliss "high bliss."