Probably from luwz (as growing there); Luz, the name of two places in Palestine -- Luz.
see HEBREW luwz
II. לוּז proper name, of a location 1. former name of Bethel Genesis 28:19 (J), 35:6 (E), 48:3 (P), Joshua 18:13 (twice in verse) (P), Judges 1:23; apparently distinct from Biblical לוּ֫זָה מִבֵּיתאֵֿל Joshua 16:2 (J E; but ׳ל here perhaps explanatory gloss, see Di); ᵐ5 Λουζα, Genesis 28:19 [Ουλαμ]μαυς
2 city in hands of Hittites Judges 1:26 (on conjectures as to site see GFM); ᵐ5 Λουζα.
לוח (√ of following, meaning unknown; compare perhaps Arabic shine, gleam, flash (of star, lightning, etc.), or Syriac wipe out, efface with reference to smooth surface; but this = לחה).