The Collaborative International Dictionary of English v.0.48:
grantor \grant"or\ (gr[.a]nt"[^o]r), n. (Law) The person by whom a grant or conveyance is made. [1913 Webster]WordNet (r) 3.0 (2006):
grantor n 1: a person who makes a grant in legal form; "conveyed from grantor to grantee"