Leer
mid 16th century (in the general sense ‘look sideways or askance’): perhaps from obsolete leer ‘cheek’, from Old English hlēor, as though the sense were ‘to glance over one's cheek’.
wiktionary
Exact development uncertain, but apparently from a verb *leer(“to make a face”), from leer(“face”).
From Middle English ler, leor(“face, cheek”), from Old English hlēor(“face, cheek, profile”), from Proto-Germanic *hleuzą(“ear, cheek”), from Proto-Indo-European *ḱlews-(“temple of the forehead, cheek”), from Proto-Indo-European *ḱlewe-, *ḱlew-(“to hear”). Cognate with Scots lire, lere(“face, appearance, complexion”), Dutch lier(“cheek”), Swedish lyra(“pout”), Norwegian lia(“hillside”), Icelandic hlýr(“the face, cheek, countenance”). Related to Old English hlyst(“sense of hearing, listening”) and hlysnan(“to listen”). More at list, listen.
From Middle English lere, from Old English ġelǣr, *lǣre(“empty, void, empty-handed”), from Proto-Germanic *lēziz, *lēzijaz(“empty”), from Proto-Indo-European *les-(“to collect, pick”). Cognate with Dutch laar(“a clearing in the woods”), German leer(“empty”). Related to Old English lesan(“to gather, collect”). More at lease.
From Middle English leren, from Old English lǣran(“to teach, instruct, guide, enjoin, advise, persuade, urge, preach, hand down”), from Proto-Germanic *laizijaną(“to teach”), from Proto-Indo-European *leis-(“track, footprint, furrow, trace”). Cognate with Dutch leren(“to teach”), German lehren(“to teach”), Swedish lära(“to teach”). Related to Old English lār(“lore, learning, science, art of teaching, preaching, doctrine, study, precept, exhortation, advice, instigation, history, story, cunning”). See lore.
See lehr.
etymonline
leer (v.)
1520s, "to look obliquely" (since 18c. usually implying a lustful, wolfish, malicious intent), probably from Middle English noun ler "cheek," from Old English hleor "the cheek, the face," from Proto-Germanic *hleuza- "near the ear," from *hleuso- "ear," from PIE root *kleu- "to hear." If so, the notion is probably of "looking askance" (compare the figurative development of cheek). Related: Leered; leering.
leer (n.)
"a significant glance, amorous or malign or both," 1590s, from leer (v.).
