The Collaborative International Dictionary of English v.0.48:
Nominalist \Nom"i*nal*ist\, n. (Metaph.) One of a sect of philosophers in the Middle Ages, who adopted the opinion of Roscelin, that general conceptions, or universals, exist in name only. --Reid. [1913 Webster]WordNet (r) 3.0 (2006):
nominalist n 1: a philosopher who has adopted the doctrine of nominalism