Dictionary > Viable


viable definition

In biology, the word viable pertains to a life form, such as a cell, that is alive or capable of sustaining life. In the background is the electron micrograph of a cluster of E. coli, magnified 10,000 times.

Viable definition

In biology, the word viable pertains to a life form, such as a cell, that is alive or capable of sustaining life. It may also pertain to an embryo, fetus, or newborn that is able to live on its own or outside the uterus. In natural selection, it describes a species that has survived over wide geographical limits.

General context

The term “viable”  came from the Mediaeval Latin vitabilis, meaning “capable of life” or the Latin vita, meaning “life”. Thus, to answer the question “what does viable mean”, the word is used to describe something (e.g. an idea or a proposition) that is feasible or capable of being done.

Usage in cell biology

In biology, its meaning is associated with a life form that has the capacity to sustain growth, development, or reproduction. Examples are viable cells, seeds, eggs, etc. that can sustain life or can stay alive. It is, in fact, used to measure the number of cells that manifest life and growth in a given area or volume. The value is referred to as the viable cell count, a useful measure in the plaque assay method. It reflects the number of cells that are alive.

Usage in obstetrics/gynecology

In obstetrics and gynecology, the term is used to describe an embryo or a fetus that can live outside the mother’s womb. A premature neonate, for instance, is viable when it is able to survive and develop when prematurely born. It means it has reached a stage when it can develop independently from its mother. Conversely, when the embryo, a fetus, or a cell does not have the capacity to sustain growth, development, or reproduction it is described as non-viable or inviable.

Usage in ecology

In ecology, a viable species pertains to a species that survived over wide geographical limits. According to the United States Forest Service’s Committee of Scientists’ Report in 1999, a viable species is defined as a species “consisting of self-sustaining and interacting populations that are well-distributed throughout the species’ range”. (Ref.1)

Synonyms of viable

  • Capable
  • Feasible
  • Sustainable

Antonyms of viable

  • Inviable
  • Nonviable

See also


  1. SPECIES VIABILITY EVALUATIONS. Frequently Asked Questions What is a species viability evaluation? (n.d.). Retrieved from https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5200616.pdf

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