Gender, for the purposes of this article, is the perceived or projected (self-identified ) masculinity or femininity of a person or characteristic. A person's gender is complex, encompassing countless characteristics of appearance, speech, movement and other factors not soley limited to physical sex, male and female, as conventionaly determined. Gender expression is commonly attributed to self-expression and innate characteristics, nature vs. nurture, and reaction to societal acceptance and oppression.
Gender is often, and incorrectly, used as a synonym for sex, referring to the physical or essential characteristics commonly used to differentiate male from female. The English noun "gender" is derived from the Old French word genre, meaning "kind of thing". It goes back to the Latin word genus (meaning "kind", "species").
This aggregate gender is often not easily categorized simply, although societys may tend to assume simple binary categorizations, as Western culture on the basis of what is often seen as natural sex division. The extreme of this belief is called essentialism, while its opposition is constructionism. Gender associations are constantly being renegotiated, as, for example, the color pink, considered masculine in the early 1900s, is now seen as feminine, and vice versa for blue. Gender is also evolving in this usage from noun to adjective: it is increasingly being seen as an attribute (like color) rather than as a distinct entity in itself.
Unlike most East Asian, African, or Native American languages, in the grammar of Indo-European languages - e.g., Sanskrit; Greek; Latin and its successors, the Romance languages; and the Slavic and Germanic Languages - nouns and pronouns are said to have a grammatical gender. This is the original use of the term as a metaphor for sex (masculine and feminine nouns from male and female people), dating to Protagoras in the fifth century, and dismay can still be found concerning the term's replacement of sex.