From Middle English schold, scholde, from Old English sċeald (“shallow”), perhaps from Proto-Germanic *skalidaz, past participle of *skaljaną (“to go dry, dry up, become shallow”), from *skalaz (“parched, shallow”), from Proto-Indo-European *(s)kelh₁- (“to dry out”). Cognate with Low German Scholl (“shallow water”), German schal (“stale, flat, vapid”). Compare shallow.