What's the "een" in Halloween?
"notched," 1660s, from Latin serratus "sawlike, notched like a saw," from serra "a saw," of unknown origin. Related: Serrated; serrating.
serrate ser·rate (sěr'āt') or ser·rat·ed (-ā'tĭd)adj.
Having or forming a row of small, sharp, projections resembling the teeth of a saw.
Having a saw-toothed edge or margin notched with toothlike projections.