1845, introduced by John Lindley in the third edition of "School Botany," from Modern Latin Orchideæ (Linnaeus), the plant's family name, from Latin orchis, a kind of orchid, from Greek orkhis (genitive orkheos) "orchid," literally "testicle," from PIE *h(o)rghi-, the standard Indo-European word for "testicle" (source also of Avestan erezi, Armenian orjik'"testicles," Old Irish uirge, Hittite arki- "testicle," Lithuanian eržilas "stallion").
The plant so called because of the shape of its root; Greek orkhis also was the name of a kind of olive, also so called for its shape. Earlier in English in Latin form, orchis (1560s), and in Middle English it was ballockwort (c. 1300; see ballocks). The modern word is marred by an extraneous -d- in an attempt to extract the Latin stem. Related: Orchidaceous.