adj

• (especially of a person) Not experiencing sexual attraction; lacking interest in or desire for sex.
  "Many asexual people experience attraction, but feel no need to act out that attraction sexually. Because they don't see a lack of sexual arousal as a problem to be corrected, asexual people focus their energy on enjoying other types of arousal and pleasure."
• (biology) Lacking distinct sex, lacking sexual organs.
• (biology) Without sexual action; reproducing by some other method than sex.
  "asexual reproduction"

noun

• (biology) A species which reproduces by asexual rather than sexual reproduction, or a member of such a species.
  "11.2 Demonstrating the Status of Long-Lived Asexuals … Indeed, if sex has so many advantages, then which special adaptations - if any - allow long-term survival without it? However, the main task of the research teams dealing with such putative ancient asexuals has thus far been to demonstrate that their respective groups (mainly bdelloids, darwinulids and certain lineages within orbatid mites) indeed merit the status."
• (rare) Something which does not have a sex, or a word which refers to such a thing.
  "[…] The masculine forms are used to a considerable extent in congruence with etymologically masculine nouns; also with etymologically feminine asexuals; e.g. se stefn L 9, 36; [...] The neuter forms are used with etymologically neuter nouns; with etymologically masculine asexuals; e.g. þ cyrtil L 6, 29; J 19, 23; þ penning L 20, 24; bēam (Lindelof p. 9) ; stān (Lindelof p. 11); and with etymologically feminine asexuals; e.g. [...]"