[Middle English loche, from Old French, possibly from Vulgar Latin *laukka, slug, loach, perhaps from Gaulish *leuca, slug, loach, feminine (attested as a feminine name Leuca), of Gaulish *leucos, bright, light (slugs perhaps originally being so called in reference to their whitish, glistening appearance, while the elongated, mottled body and barbels of Cobitis taenia, a European loach esteemed as a food fish, were later likened to the body and ommatophores of the leopard slug Limax maximus, a large, common slug of Europe); see leuk- in the Appendix of Indo-European roots.]