Gender
Before the 1950s, the term 'gender' was used only in the field of grammar, and only to distinguish a category of words that are called 'feminine nouns' from other words that are 'masculine nouns'.[1][2] Early Indo-European languages~had three genders. Languages that come from Latin like Spanish, French, and Italian have lost one, and their nouns are either feminine or masculine in gender. For example, in Spanish, 'house' (casa) is feminine, and 'day' (día) is masculine. Some languages still have three genders, like German. Outside of their grammatical category, the word 'gender' was not used to refer to people. At that time, when one spoke about someone being either 'male' or 'female', the word used was sex.