The Collaborative International Dictionary of English v.0.48:
Seamster \Seam"ster\, n. [See Seamstress.] One who sews well, or whose occupation is to sew. [Obs.] [1913 Webster]WordNet (r) 3.0 (2006):
seamster n 1: a person whose occupation is making and altering garments [syn: tailor, seamster, sartor]