as ADVERB used in comparisons to refer to the extent or degree of something.
CONJUNCTION 1) used to indicate simultaneous occurrence. 2) used to indicate by comparison the way that something happens. 3) because. 4) even though.
PREPOSITION 1) used to refer to the function or character of someone or something: it came as a shock. 2) during the time of being.
as for — Cf. ↑as for
as yet — Cf. ↑as yet
ORIGIN Old English, «similarly».

English terms dictionary. 2015.