Monogenes

The Greek word mo·no·ge·nesʹ is defined by lexicographers as “single of its kind, only,” or “the only member of a kin or kind.” (Thayer’s Greek-English Lexicon of the New Testament, 1889, p. 417; Liddell and Scott’s Greek-English Lexicon, Oxford, 1968, p. 1144) The term is used in describing the relation of both sons and daughters to their parents.
Monogenes in Christianity:
The Scriptures speak of “the only-begotten son” of a widow who lived in the city of Nain, of Jairus’ “only-begotten daughter,” and of a man’s “only-begotten” son whom Jesus cured of a demon. (Lu 7:11, 12; 8:41, 42; 9:38) The Greek Septuagint uses mo·no·ge·nesʹ when speaking of Jephthah’s daughter, concerning whom it is written: “Now she was absolutely the only child. Besides her he had neither son nor daughter.”—Jg 11:34.