The Collaborative International Dictionary of English v.0.48:
Captivating \Cap"ti*va`ting\, a. Having power to captivate or charm; fascinating; as, captivating smiles. -- Cap"ti*va`ting*ly, adv. [1913 Webster]WordNet (r) 3.0 (2006):
captivatingly adv 1: in a bewitching manner; "she was bewitchingly beautiful" [syn: bewitchingly, captivatingly, enchantingly, enthrallingly]