desirable adj.

"to wish or long for, express a wish to obtain," c. 1200, desiren, from Old French desirrer (12c.) "wish, desire, long for," from Latin desiderare "long for, wish for; demand, expect," the original sense perhaps being "await what the stars will bring," from the phrase de sidere "from the stars," from sidus (genitive sideris) "heavenly body, star, constellation" (but see consider). Related: Desired; desiring.

"state or condition of being worthy to be desired," 1824; see desirable + -ity.

1660s, "not to be desired, objectionable," from un- (1) "not" + desirable. The noun meaning "undesirable person or thing" is first attested 1883. Undesired "not asked or invited" is recorded from late 15c.