Word Origin & History
early 14c., "spider threads spun in fields of stubble in late fall," apparently from gos "goose" + sumer "summer" (cf. Swed. sommertrad "summer thread"). The reference might be to a fancied resemblance of the silk to goose down, or because geese are in season then. The Ger. equivalent mädchensommer
(lit. "girls' summer") also has a sense of "Indian summer," and the Eng. word may originally have referred to a warm spell in autumn before being transferred to a phenomenon especially noticable then. Meaning "anything light or flimsy" is from c.1400. The adj. sense "filmy" is attested from 1802.