Is it ensure, insure, or assure?
1789, "action or fact of being sexual;" see sexual + -ity. Meaning "capability of sexual feelings" is from 1879. Meaning "sexual identity" is by 1980.
sexuality sex·u·al·i·ty (sěk'shōō-āl'ĭ-tē)n.
The condition of being characterized and distinguished by sex.
Concern with or interest in sexual activity.
Sexual character or potency.