Sherlock

c. 1200, "exempt, free from guilt" (as in Sheer Thursday, the Thursday of Holy Week, the day before the Crucifixion); later schiere "thin, sparse" (c. 1400), a variant of skere, from late Old English scir "bright, clear, gleaming; translucent; pure, unmixed." The Middle English word might also be from or influenced by the Old Norse cognate scær "bright, clean, pure." Both of these are from Proto-Germanic *skeran (source also of Old Saxon skiri, Old Frisian skire, German schier, Gothic skeirs "clean, pure"), from PIE root *sker- (1) "to cut."

The sense of "absolute, utter" (sheer nonsense) developed by 1580s, probably from the notion of "unmixed, uncombined with anything else;" that of "very steep, straight up and down" (a sheer cliff) is recorded from 1800, probably from notion of "continued without halting." Especially of textile fabrics, "diaphanous, very thin and delicate," from 1560s. As an adverb from c. 1600; also sheerly.

"tress of hair," Old English locc "lock of hair, curl" (plural loccas), from Proto-Germanic *lukkoz (source also of Old Norse lokkr, Old Saxon, Old Frisian, Dutch lok, Old High German loc, German Locke "lock of hair"), a word of uncertain origin. According to OED, perhaps from a PIE *lugnos- and related to Greek lygos "pliant twig, withe," Lithuanian lugnas "flexible" (see reluctance).