flittermouse means A bat (a flying mammal). Lexicurio rates it Sui generis — a strength score of 91 out of 100.
Why “flittermouse” is a great word
A folk name for a bat, formed from the obsolete verb 'flitter' (to flutter) and 'mouse,' a calque of Middle Dutch *vledermuys* (from *vledderen*, 'to flutter,' and *muys*, 'mouse'), cognate with German *Fledermaus* and Swedish *fladdermus*. Unlike the bluntly standard 'bat' or the clinical 'chiropteran,' 'flittermouse' is an artifact of direct observation, stitching together plain words for its two most evident traits. It is the flickering silhouette that snatches a moth above a pond, the soft rustle in a barn's rafters at twilight, the scrap of living velvet tumbling through the dusk—a testament to the human habit of naming the strange by the familiar, a whispered secret of the encroaching night.
Etymology
From flitter + mouse (compare flickermouse, flindermouse), after Middle Dutch fleddermuys, vledermuys, vlermuys (Modern Dutch vleermuis), from vledderen, vlederen (“to flutter, float, hover”) + muys (“mouse”). Cognate with West Frisian flearmûs (“bat”), Middle Low German vledermūs (“bat”), German Fledermaus (“bat”), Swedish fladdermus (“bat”) and flädermus (“bat”). More at flitter, flutter, flatter, mouse.
noun
- A bat (a flying mammal).“I thank thee, gentle flittermouse, for these so pleasant memories. Have you ever caught and examined a flittermouse?”