'Âchôth (אָחוֹת, Strong's #269), “sister.” Like the words for “brother” and “father,” this noun is common to many Semitic languages. Whereas “brother” appears 629 times, “sister” occurs only 114 times. The usage is rare in the poetic literature with the exception of the Song of Solomon (7 times). The first occurrence is in Gen. 4:22: “And Zillah, she also bare Tubal-cain, an instructor of every artificer in brass and iron: and the sister of Tubalcain was Naamah.”

The translation of “sister” for 'âchôth is only the beginning. In Hebrew custom the word was a term employed to refer to the daughter of one’s father and mother (Gen. 4:22) or one’s half-sister (Gen. 20:12). It may also refer to one’s aunt on the father’s side (Lev. 18:12; 20:19) or on the mother’s side (Lev. 18:13; 20:19).

The use of 'âchôth more generally denotes female relatives: “And they blessed Rebekah, and said unto her, Thou art our sister, be thou the mother of thousands of millions, and let thy seed possess the gate of those which hate them” (Gen. 24:60). This meaning lies behind the metaphorical use, where two divisions of a nation (Judah and Israel; Jer. 3:7) and two cities (Sodom and Samaria; Ezek. 16:46) are portrayed as sisters—Hebrew names of geographical entities are feminine.

The more specialized meaning “beloved” is found only in Song of Sol. 4:9: “Thou hast ravished my heart, my sister [or beloved], my spouse; thou hast ravished my heart with one of thine eyes, with one chain of thy neck.” Here 'âchôth is used as a term of endearment rather than a term for a blood relative.

The Septuagint translates the word adelphe (“sister”).

Bibliography Information
Vines, W. E., M. A. Entry for 'Sister'. Vine's Expository Dictionary of OT Words. https://www.studylight.org/dictionaries/eng/vot/s/sister.html. 1940.

Bible Dictionaries Sister

Vine's Expository Dictionary of OT Words

Bible Dictionaries
Sister