DictionaryAI

species

noun
SPEE-sheez/ˈspiːʃiːz/

Pluralspecies

9 meanings of species

Practice

  1. 1
    animal or plant typenouncountable
    A group of living things that can breed together and produce fertile young; in classification, the basic rank just below genus.

    Horses and donkeys are separate species, since the mules they produce are almost always sterile.

    Biologists described a new frog species after years of fieldwork.

    UsageOne species, many species: the singular also ends in -s (not incorrect: a specie).

    Note

    The usual test is breeding: animals belong together when their young are fertile. In classification, the species is also the rank just below genus. Used without a qualifier, "her species" can mean humankind, as when Sister Louise in Letitia Elizabeth Landon's Francesca Carrara (1834) feels "raised above her species." Science fiction stretches the word to "galactic species."

    Checked 2 Nov 2026 · 2 facts

    • Producing fertile offspring is a usual test of membership in the same biological species. openstax.org
    • Species ranks immediately below genus in the principal classification hierarchy. en.wikipedia.org
  2. 2
    nouncountable
    A particular kind, sort, or type of thing.

    Her remarks were a peculiar species of flattery.

    The contract contained a species of clause rarely seen in modern agreements.

    UsageUsually a species of + noun: a peculiar species of flattery.

    Similarkind, sort, type, variety, form

    Note

    The broad sense that the scientific ones later narrowed. Latin speciēs meant "appearance" or "quality," from speciō, "see," so a kind was first a matter of how a thing looks.

    Checked 2 Nov 2026 · 2 facts

    • The general classificatory sense preceded the specialized biological sense. content.ucpress.edu
    • Species derives from Latin speciēs, meaning appearance or quality, from speciō, meaning see; the connection with appearance explains the note's reference to looks. en.wiktionary.org
  3. 3
    chemistry particlenouncountable
    A particular kind of atom, molecule, ion, or other particle, considered as a distinct type in chemistry.

    Chemists identified the reactive species responsible for the color change.

    Several charged species coexist in the solution at equilibrium.

    Note

    Chemists use it when they need one word for any particle type, whatever its kind: atom, ion, molecule or radical. That lets them say a solution holds several species at once. It usually takes an adjective naming behavior or charge, as in reactive species or ionic species. Because the plural is the same word, "the species present" can mean one particle type or many.

    Checked 31 Oct 2026 · 2 facts

    • A chemical species denotes a type or ensemble of chemically identical entities; the general term for an individual particle is molecular entity. iupac.qmul.ac.uk
    • Several chemical species can coexist in a solution. chem.purdue.edu

Practice

Can you tell the meanings of species apart? Answer 4 quick questions from this page, or write your own sentence and AI will check it.

Origin

The word is Latin speciēs, meaning "appearance" or "quality." Latin built it on speciō ("see") with the abstract-noun suffix -iēs. Species and spice are doublets.

Checked 1 Nov 2026 · 4 facts