A sister is usually a female human or female animal who shares either one or more biological parents with another person. Although the word technically refers to a close familial relationship, sometimes it can be used quite comfortably to refer loosely to non familial relationships as well. Even a full sister, a second degree relative, is a qualified member of that family whose parents are legally married.
All mammals have a variety of identifying characteristics, including males and females. Among humans, however, females are the only ones that can breed under certain conditions. Historically, it was a common practice for siblings to care for one another after birth, although this was not always the case. Many female siblings lived in different households before marriage and during their younger years. It was not unusual for a female sibling to stay home to care for her younger sister or live with her father or mother.
The etymology of the word sister can derive from Latin and Greek words, especially from the Greek word seis meaning “one’s own life.” This word became related to the English word’sister’ in the middle ages, probably because of one of the wives of the Roman Emperor, Trajan. When the English language began to develop in the fourteenth century, the word sister began to be used to mean “a female child born out of wedlock.” From this time on, the etymology of sister began to imply “a female relation of the opposite sex,” while the etymology of suster came to imply “fruitful union.” Most scholars agree that suster should be considered as a synonym for sister, since in most cases the two words share the same meaning.
From the middle ages on, it became customary for a brother to accompany his sister on trips, and this custom grew into the custom of travelling in company. A man going on a business trip would have his male sister accompany him, while a man going on a fishing expedition would have his male sister accompany him. As time went on, the practice of travelling with one’s sister continued to be accepted, though not as widely prevalent as it had been in the past. In the early twentieth century, however, the concept of a sister company was used to describe a married couple who travelled together.
The etymology of sister nouns that incorporate the words sweary, fainting, and dizziness indicate that these words originated from French, German, and Italian. These words likely originated in the Middle Ages, as these are words that usually accompanied some other form of oaths or promises. However, they are more commonly related to the etymology of sisterhood, coming from French words that meant ‘fellow-feeling, a close sisterhood, or ‘our sisterhood’. Also, the word’sister’ itself is from the Latin word’sepultus’, which meant ‘alone, solitary, remote’. From the etymology of this root word, it appears to have taken on a different meaning than it does today, referring to someone living alone and remote from loved ones.
The etymology of sister nouns that incorporate words derived from French, German, and Italian also show that they were originally formed from Latin roots, but this word eventually became corrupted. For example, the word’semi’ comes from’same’, while’mets’ comes from’mets’, while’sisters’ is from’sister’. It seems that’sister’ came into being through Latin origins, but the word itself may have been influenced by’sorcere’,’sister’, ‘aunts’, ‘companion’, ‘wives’ in early Greek and Roman times. In early medieval Europe, the word for brother was’surmise’; it seems that the spelling change from’sister’ to’surmise’ was prompted by the French word’sur missi’. From the word itself, however, the meaning must have been something closely related to ‘ally’.