*blasaz

Probably from Proto-Indo-European *bʰel- (‘to blaze; glow; bright flame; white’), but the exact formation is uncertain. A plausible speculative analysis derives the word from a zero-grade preform *bʰl̥- with an old adjectival *-s-extension, e.g. pre-Germanic **bʰl̥-s-ó-s. This would fit both the Proto-Germanic vocalism and the semantics suggested by Greek φάλαρος (phắlāros, ‘having a patch of white or a white spot’) and later Proto-Germanic forms referring to a white blaze or forehead-mark on animals (e.g. Old Norse blesi, Dutch bles, English blaze, all based on a further derivation from *blasaz). The original sense may therefore have been ‘white-marked, blaze-marked’, only later generalized to ‘pale, whitish’.