1901: William Alexander Dorland: "Heterosexuality"
In 1901, Dorland's Medical Dictionary, published in Philadelphia, defined "Heterosexuality" as:
Abnormal or perverted appetite toward the opposite sex.
Dorland's heterosexuality, a new sort of "appetite," was here clearly identified with an "opposite sex" hunger. But that craving was still aberrant. The heterosexual appetite was not, for the first time in print, spoken of as an entity: "heterosexuality."
Dorland's calling heterosexuality "abnormal or perverted" is, according to the old Oxford English Dictionary's first Supplement (1933), a "misapplied" definition. But that OED, is mistaken. Dorland's is a perfectly legitimate understanding of heterosexuality according to a traditional procreative norm.
1 Adapted from Jonathan Ned Katz, The Invention of Heterosexuality (NY: Dutton, March 1995), page 86, notes 11 and 12 on page 223, citing William Alexander Dorland, The American Illustrated Medical Dictionary, second edition, (Philadelphia: W. B. Saunders, 1901), page 300.
2 James A. H. Murray, etc., eds. A Supplement to the Oxord English Dictionary (Oxford, England: Clarendon Press, 1933), page 460.