olemus
Wiktionary:
1. (countable) a category into which sexually-reproducing organisms are divided on the basis of their reproductive roles in their species
The effect of the medication is dependent upon age, sex, and other factors.
2. (countable) another category, especially of humans and especially based on sexuality or gender roles
3. (countable) the members of such a category, taken collectively
4. (uncountable) the distinction and relation between these categories, especially in humans; gender

ISO/IEC 2382-37:
liigitus isas-, emas- või muuks kategooriaks esmaste sootunnuste ja/või genotüübi hindamise põhjal
Märkus 1 Sugu määratakse üldiselt sündimisel, kolmandapoolse otsusega.
Märkus 2 Esmased sootunnused on kõik otseselt sigimisega seotud kehastruktuurid.
= classification as male, female or some other category based on an assessment of primary sexual characteristics or genotype or both
Note 1. Sex is generally assigned at birth by a third-party assessment.
Note 2. Primary sexual characteristics are any of the body structures directly concerned with reproduction.

näide
isikuandmete element: mees/naine

ülevaateid
https://en.wikipedia.org/wiki/Sex