A grammatical category found in many languages in which a noun, pronoun, article and adjective is masculine, feminine or neuter, although some languages only distinguish between masculine and feminine.
This distinction does not occur in English. The only times that gender is shown in English is when the noun refers to a male or female animal, person, etc.:
lion (male) lioness (female)
waiter (male) waitress (female)
Many of these distinctions are being ignored by many speakers nowadays, who use 'actor' for both men and women, rather than using 'actress' for women.