The Collaborative International Dictionary of English v.0.48:
Seaport \Sea"port`\ (s[=e]"p[=o]rt`), n. A port on the seashore, or one accessible for seagoing vessels. Also used adjectively; as, a seaport town. [1913 Webster]WordNet (r) 3.0 (2006):
seaport n 1: a sheltered port where ships can take on or discharge cargo [syn: seaport, haven, harbor, harbour]