phe·​no·​type | \ ˈfē-nə-ˌtīp How to pronounce phenotype (audio) \
plural phenotypes

Definition of phenotype

 (Entry 1 of 2)

1 : the observable characteristics or traits of an organism that are produced by the interaction of the genotype and the environment : the physical expression of one or more genes Considering that modern maize is a tetraploid, it is remarkable how many single gene mutations cause profound changes in phenotype.— Virginia Walbot A breed is a group of genetically related individuals with a common phenotype—physical characteristics, such as ear and muzzle shapes, and behavioral tendencies, such as those of a retriever to swim or a border collie to herd …— Mark Derr Phenotype is how that DNA physically manifests itself—in this case, as the susceptibility to disease, or the progression of disease, or the susceptibility of the disease itself to treatment, all of which likely have a genetic component.— Gary Taubes
2 : the observable characteristics or traits of a disease … a mild disorder whose clinical phenotype overlaps with that of the Marfan syndrome …— Petros Tsipouras et al.


phenotyped; phenotyping; phenotypes

Definition of phenotype (Entry 2 of 2)

transitive verb

: to determine, analyze, or predict all or part of a phenotype of Red cells were phenotyped as M + or M -.— Raymond L. Comenzo et al. … a team … recently decided to examine the data collected so far to determine how many of the phenotyped mice had eye problems.— Michelle Wong The asthma in these patients was not phenotyped. We do not have any information regarding the eosinophil count or other markers such as exhaled oral nitric oxide in these subjects.— Faria Nasim

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Other Words from phenotype


phenotypic \ ˌfē-​nə-​ˈti-​pik How to pronounce phenotypic (audio) \ or less commonly phenotypical \ ˌfē-​nə-​ˈti-​pi-​kəl How to pronounce phenotypical (audio) \ adjective
phenotypic variation phenotypic expression
phenotypically \ ˌfē-​nə-​ˈti-​pi-​k(ə-​)lē How to pronounce phenotypically (audio) \ adverb
phenotypically similar populations

Examples of phenotype in a Sentence

Recent Examples on the Web: Noun Also intriguing is the woman’s phenotype, or physical characteristics, as suggested by her genome. Matt Simon, Wired, "What a 5,700-Year-Old Piece of Gum Reveals About Its Chewer," 17 Dec. 2019 Recessive genes only manifest as a noticeable phenotype when both of an individual’s two copies of a gene are the same, so the duplicate genes passed down through inbreeding make a recessive trait statistically more likely to surface. Lila Thulin, Smithsonian, "The Distinctive ‘Habsburg Jaw’ Was Likely the Result of the Royal Family’s Inbreeding," 4 Dec. 2019 According to Cosmos, the scientists’ findings indicate that hosts’ phenotypes, or observable physical properties, may influence crypt-keepers’ victim selection more than the manipulative parasite’s own specialized skill set. Meilan Solly, Smithsonian, "Parasitic Crypt-Keeper Wasp Manipulates the Minds of Seven Fellow Insect Species," 27 Sep. 2019 All the bacteria in this colony could be expected to show the same behaviors, physiology and physical appearance — the same phenotype — when placed in identical environments. Quanta Magazine, "Bacterial Clones Show Surprising Individuality," 4 Sep. 2019 Debra Meyer With one or more of the male ancestors in my maternal lineage being Khoi-San, the cross-over sharing of chromosomal DNA between parents explains the Khoi-San phenotype—that is, observable, physical characteristics – in my family. Debra Meyer, Quartz Africa, "How an African scientist used mitochondrial DNA to discover she had ancestral South Asian roots," 6 Sep. 2019 Some evolutionary biologists have hoped to use the scores to get a better picture of the phenotypes that were encoded in ancient genomes, and to better understand histories of adaptation in various populations. Quanta Magazine, "New Turmoil Over Predicting the Effects of Genes," 23 Apr. 2019 So the new allelic frequencies will remain p and q in the next generation, and will keep the phenotype ratios stable indefinitely, as long as one allele is not favored by evolution above its initial level. Quanta Magazine, "Solution: ‘Are Genes Selfish or Cooperative?’," 29 Sep. 2017 Second, in 2006, researchers demonstrated that gut microbes could cause changes in a host’s phenotype, such as obesity. Jason Pontin, WIRED, "The 19th-Century Crank Who Tried to Tell Us About the Microbiome," 15 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'phenotype.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of phenotype


1910, in the meaning defined at sense 1


1959, in the meaning defined above

History and Etymology for phenotype


German Phänotypus, from Greek phainein to show + typos type

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Time Traveler for phenotype

Time Traveler

The first known use of phenotype was in 1910

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Statistics for phenotype

Last Updated

27 Jan 2020

Cite this Entry

“Phenotype.” Dictionary, Merriam-Webster, Accessed 19 Feb. 2020.

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More Definitions for phenotype


phe·​no·​type | \ ˈfē-nə-ˌtīp How to pronounce phenotype (audio) \

Medical Definition of phenotype

1 : the observable characteristics or traits of an organism that are produced by the interaction of the genotype and the environment : the physical expression of one or more genes Considerable data on ABO blood group phenotypes and alleles now exist showing marked differentiation between geographical areas such as Europe and Asia …— J.A. Beardmore et al. The mice also developed an osteoporotic phenotype that was not due to a defect in osteoblast differentiation, but rather to a marked decline in the output of bone matrix per osteoblast.— Patrick Ducy et al.
2 : the observable characteristics or traits of a disease … a mild disorder whose clinical phenotype overlaps with that of the Marfan syndrome …— Petros Tsipouras et al.

Other Words from phenotype

phenotypic \ ˌfē-​nə-​ˈtip-​ik How to pronounce phenotypic (audio) \ also phenotypical \ -​i-​kəl How to pronounce phenotypical (audio) \ adjective
phenotypically \ -​i-​k(ə-​)lē How to pronounce phenotypically (audio) \ adverb

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More from Merriam-Webster on phenotype

Nglish: Translation of phenotype for Spanish Speakers

Britannica English: Translation of phenotype for Arabic Speakers Encyclopedia article about phenotype

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