Definition of "coster"

It was nearly eleven o'clock now, and he strolled out again. In the little fair created by the costers' barrows the evening only seemed beginning; and the naphtha flares made one's eyes ache, the men's voices grated harshly, and the girls' faces saddened one.

1918, W[illiam] B[abington] Maxwell, chapter VII, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company