Deidra is a modern English variant of the name Deirdre, originating from the Old Irish name Derdriu. The etymology of Derdriu is uncertain, though it may be derived from the Irish element der meaning "daughter." Deirdre is a tragic figure in Irish mythology, the heroine of the Ulster Cycle, who was betrothed to King Conchobar but fell in love with Naoise. After Conchobar killed Naoise, Deirdre died of a broken heart. Despite its ancient mythological roots, Deirdre (and its variants like Deidra) was rarely used as a given name until the 20th century. It gained popularity largely due to early 20th-century literary works: William Butler Yeats' play Deirdre (1907) and J. M. Synge's Deirdre of the Sorrows (1910). These works revived interest in the name, eventually leading to its adoption in the English-speaking world. Deidra, along with related forms such as Deidre and Deitra, became used in the latter half of the 20th century, particularly in the United States. The spelling “Deidra” traces its earliest known usage in U.S. birth records to the mid-1940s, though the name spread modestly without reaching widespread prevalence. Meaning: uncertain, possibly "daughter" (from Old Irish der) Origin: Variant of Deirdre, from Irish legend Type: Given name, feminine Usage Regions: English-speaking countries