sem·​el·​pa·​rous ˌse-ˈmel-pə-rəs How to pronounce semelparous (audio)
: reproducing or breeding only once in a lifetime
semelparous salmon

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Breaking Down Semelparous

The combining form -parous was first used in English by the 17th-century physician and writer Sir Thomas Browne, who wrote about organisms that were multiparous ("producing more than one at a birth"), oviparous ("producing eggs that develop outside the maternal body"), and viviparous ("producing living young instead of eggs from within the body"). The suffix is based on the Latin verb parere, meaning "to give birth to," which is also a relative of the word that gave us parent. Semelparous, the youngest offspring of -parous, was born in 1954. Its other parent is semel, the Latin word for "once."

Examples of semelparous in a Sentence

Recent Examples on the Web Smaller semelparous mammals ultimately perish from a flood of stress hormones after mating, writes Donna Lu for the Guardian. Margaret Osborne, Smithsonian Magazine, 2 Feb. 2023 The practice isn’t unheard of: 19 marsupial species in the family Dasyuridae, which includes quolls, are semelparous. Margaret Osborne, Smithsonian Magazine, 2 Feb. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'semelparous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin semel "a single time, once" (from the same base as simul "together, at the same time," similis "having characteristics in common, like") + -parous — more at similar

Note: The prehistory of semel in relation to simul and similis is uncertain. M. Leumann proposes semel < *semels < *semalis, with *-is after bis "twice" (Lateinische Laut- und Formenlehre [Munich, 1977], pp. 141-42, 494). G.E. Dunkel (Lexikon der indogermanischen Partikeln und Pronominalstämme, Heidelberg, 2014) has completely different analyses for similis/simul and semel—see note at similar.

First Known Use

1954, in the meaning defined above

Time Traveler
The first known use of semelparous was in 1954


Dictionary Entries Near semelparous

Cite this Entry

“Semelparous.” Dictionary, Merriam-Webster, Accessed 25 Jun. 2024.

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