shiku-adjective (archaic)
Archaic shiku adjective; used in classical Japanese. In modern Japanese, 悪い (わるい) is the standard word for 'bad'.
In classical Japanese, あし was written 悪し and used to mean 'bad' or 'evil'.
The classical adjective 悪し means “bad” or “evil” and belongs to the ク活用 class. It now survives chiefly in fixed expressions such as よしあし and あしからず; modern 悪い developed from a different older adjective, わろし.