seamy adj.

Middle English seme, from Old English  seam, "seam of a garment, suture, junction made by sewing together the edges of two pieces of cloth or two edges of the same piece," from Proto-Germanic *saumaz (source also of Old Frisian sam "hem, seam," Old Norse saumr, Middle Dutch som, Dutch zoom, Old High German soum, German Saum "hem"), from PIE root *syu- "to bind, sew."

Chidynge and reproche ... vnsowen the semes of freendshipe in mannes herte. [Chaucer, "Parson's Tale," c. 1386]

In Middle English also "a gash or scar" (c. 1400). Meaning "raised band of stitching on a ball" is recorded from 1888. Geological sense of "thin strata between two wider ones" is from 1590s. Figurative phrase bursting at the seams, expressive of overfullness, is by 1962. Seam-squirrel "a louse" was old U.S. slang (1893).

adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.