The Collaborative International Dictionary of English v.0.48:
Prevenient \Pre*ven"i*ent\, a. [L. praeveniens, p. pr.] Going before; preceding; hence, preventive. "Prevenient grace descending." --Milton. [1913 Webster]WordNet (r) 3.0 (2006):
prevenient adj 1: in anticipation [syn: anticipatory, prevenient]