Definify.com

Webster 1913 Edition

Adj.

[CF.

Lacking vigor; weak; spiritless.

[Obs.]

Spenser.

Free from sexual lust.

, a.

Listless; not willing. Obs.

Not vigorous.

lustless ‎(comparative more lustless, superlative most lustless)

Without sexual lust.
- 1587, Christopher Marlowe, Tamburlaine the Great
  By Mahomet my kinsman's sepulchre, / And by the holy Alcoran I swear, / He shall be made a chaste and lustless eunuch...
- 1964, J Z Eglinton, Paul Goodman, Greek Love
  But then, Bergler also claims that there are no genuinely ambi-erotic individuals, only "homosexuals who may be capable of lustless mechanical sex...
(obsolete) Lacking vigour; weak; spiritless.