From WordNet (r) 3.0 (2006):
alright
adv 1: without doubt (used to reinforce an assertion); "it's
expensive all right" [syn: all right, alright]
2: an expression of agreement normally occurring at the
beginning of a sentence [syn: very well, fine, alright,
all right, OK]
3: in a satisfactory or adequate manner; "she'll do okay on her
own"; "held up all right under pressure"; (`alright' is a
nonstandard variant of `all right') [syn: okay, O.K.,
all right, alright]
adj 1: nonstandard usage