12 letters · 22 points in Scrabble
noun a heterosexual person; someone having a sexual orientation to persons of the opposite sex
adjective sexually attracted to members of the opposite sex
originFrom hetero- + -sexual. Earliest citation from 1892, in C.G. Craddock's translation of Krafft-Ebbing's Psychopathia Sexualis.
Etymology from Wiktionary, CC BY-SA 3.0