Real Dictionary

expedient
An expedient is an action that achieves a particular purpose, but may not be morally right.
adjective: If it is expedient to do something, it is useful or convenient to do it, even though it may not be morally right.

expedient in American English
an expedient thing; means to an end
useful for effecting a desired result; suited to the circumstances or the occasion; advantageous; convenient
adjective: tending to promote some proposed or desired object; fit or suitable for the purpose; proper under the circumstances
noun: a means to an end

expedient in British English
adjective: suitable to the circumstances; appropriate
noun: something suitable or appropriate, esp something used during an urgent situation