\Rear"mouse`\, Reremouse \Rere"mouse`\, n. [AS.
hr[=e]rem[=u]s; probably fr. hr[=e]ran to agitate, stir (akin
to G. r["u]hren, Icel. hr[ae]ra) + m[=u]s mouse.] (Zo["o]l.)
The leather-winged bat ({Vespertilio murinus}). [Written also
{reermouse}.]