What's the "een" in Halloween?
Old English sear "dried up, withered, barren," from Proto-Germanic *sauzas (cf. Middle Low German sor, Dutch zoor), from PIE root *saus- "dry" (cf. Sanskrit susyati "dries, withers;" Old Persian uška- "dry" (adj.), "land" (n.); Avestan huška- "dry;" Latin sudus "dry"). A good word now relegated to bad poetry. Related to sear. Sere month was an old name for "August."
The entire sequence of ecological communities successively occupying an area from the initial stage to the climax community. See more at succession.