flina

From Proto-Germanic *flinōną (“to bare (one's teeth), smile”), from a Proto-Indo-European *pley- (“bare, bald, flat”). Cognate with Elfdalian flinå (“smile”); outside of Germanic, compare Lithuanian pli̇̀kas (“bald”), Latvian pliks (“bare, bald”). The root may be further connected to Proto-Indo-European *(s)pley- (“to cleave, to split off, to cast off”) (that smiling is a "splitting" of one's mouth), see Proto-Germanic *splītaną (“to split”) for more on the root.