adjective/ɑ̃.da.lu/
Andalusian (of, from or relating to the autonomous community of Andalusia, Spain)
Related: arabe andalou, sauce andalouse
Borrowed from Spanish andaluz. The singular in -ou is probably a backformation from the plural. It became common first in the equestrian sense, where the feminine is rare; this then caused the spelling inconsistency between masculine and feminine forms (compare also absous, coi, esquimau, favori).