The Collaborative International Dictionary of English v.0.48:
jampack \jampack\ v. t. 1. to stuff; to fill completely and tightly; to jam[1]. Syn: jel, gel. [WordNet 1.5]WordNet (r) 3.0 (2006):
jampack v 1: crowd or pack to capacity; "the theater was jampacked" [syn: jam, jampack, ram, chock up, cram, wad]