means The act, or the resulting line, of joining or fastening material with thread or yarn pulled through by a needle.

from From Old English 'stice,' a prick or puncture — the literal sting of a needle going in — which is closely related to 'stick' (to pierce or stab) and a cousin of German 'Stich,' a sting or stab. The thread came later; the sharp little wound came first, so every seam is really a tidy row of tiny stabs.