Middle English gossomer described mild late-autumn or early-winter weather and floating cobwebs. Its parts mean goose and summer.
The explanation linking the webs with goose down or the season is only proposed. The component meanings are the scored facts.
Sources
- Merriam-Webster: gossamer
Middle English gos and somer mean goose and summer; the connection between mild weather and floating webs is qualified.
- Online Etymology Dictionary: goose
Also built on *goose* (Old English *gos*): goosebumps