dichotomy

noun

di·​chot·​o·​my dī-ˈkä-tə-mē 

 also  də-

plural dichotomies

1

a

: division into two especially mutually exclusive or contradictory groups or parts

the dichotomy between theory and practice

It's the dichotomy of what is shown to Wall Street and to the tax man.

—Erik Sherman

b

: differentiation into two contrasted or sharply opposed groups

… the assumed left-right dichotomy of the brain—with verbal abilities concentrated in the left hemisphere and visual-spatial abilities clustered in the right—is an oversimplification.

—Gregory Hickok et al.

… it helps to understand how deeply entrenched in our intellectual history the false dichotomy of nature vs. nurture became.

—Matt Ridley

2

: something with seemingly contradictory qualities

It's a dichotomy, this opulent Ritz-style luxury in a place that fronts on a boat harbor …

—Jean T. Barrett

3

astronomy : the phase of the moon or of an inferior planet (such as Mercury or Venus) in which half its disk appears illuminated

4

biology

a

: bifurcation

especially : repeated bifurcation (as of a plant's stem)

b

: a system of branching in which the main axis forks repeatedly into two branches

c

: branching of an ancestral line into two diverging branches

Did you know?

Dichotomy and False Dichotomy

The two most commonly used senses of dichotomy are easily (and often) confused. The older one refers to the division of something into two groups that often are mutually exclusive or contradictory (as in “the dichotomy between good and evil”). Like trichotomy (meaning “division into three parts”), this sense denotes separation into different elements, but it adds the connotation of oppositeness. The newer sense of dichotomy denotes a thing that appears to have contradictory qualities, such as a lemonade stand found in a war zone. Dichotomy is frequently found in the company of the word false; a false dichotomy is a kind of fallacy in which one is given only two choices when in fact other options are available.

Synonyms of dichotomy

• paradox

Examples of dichotomy in a Sentence

The amusing spectacle of the recent presidential vote in Florida should remind us of the persistence of the federal-state dichotomy. —Eugene Genovese, Atlantic, March 2001

At the close of this millennium, the favored dichotomy features a supposed battle called "the science wars." —Stephen Jay Gould, Science, 14 Jan. 2000

… to insist on its being either symbol or fact is to dwell needlessly on a false dichotomy. —Simon Schama, The Embarrassment of Riches, 1988

… the Inuit concept of their environment was centred around the dichotomy between land and sea. —Ian Hodder, Reading the Past, 1986

Her essay discusses the dichotomy between good and evil in the author's novels.

her outfit is a sartorial dichotomy: an elegant gown and ratty old tennis shoes

Recent Examples on the Web

All under Guadagnino’s scrupulous direction and cinematographer Malik Sayeed’s (Belly) visualization, the performative guise of Ivy League school decorum delivers as the perfect dichotomy to the serious nature of what these characters put each other through. —Malik Peay, Essence, 9 Oct. 2025

The house’s spectacle in Grand Palais and fashion show is rooted in technological, futuristic and artisanal imaginations, while experiencing a dichotomy with the reinvention of clothing, which carries a sensitive memory of the past — projecting a constellation of colors, codes and values. —Martino Carrera, Footwear News, 7 Oct. 2025

There should be no dichotomy here. —Rick Tumlinson, Space.com, 25 Sep. 2025

That dichotomy was really interesting to me. —Lily Ford, HollywoodReporter, 24 Sep. 2025

Word History

Etymology

borrowed from New Latin dichotomia, borrowed from Greek dichotomía "division into two parts (of the moon, in logic), bisection," from dichótomos "cut in half, dichotomous" + -ia -ia entry 1

First Known Use

1588, in the meaning defined at sense 1

Phrases Containing dichotomy

• false dichotomy

Rhymes for dichotomy

• craniotomy
• lithotomy
• phlebotomy
• tenotomy
• vagotomy
• episiotomy
• laparotomy
• osteotomy
• thoracotomy
• tracheotomy
• ovariotomy

Kids Definition

dichotomy

noun

di·​chot·​o·​my -mē 

plural dichotomies

: a division into or distinction between two groups that differ greatly

the dichotomy between good and evil

Medical Definition

dichotomy

noun

di·​chot·​o·​my

dī-ˈkät-ə-mē also də-

plural dichotomies

: a division or forking into branches

especially : repeated bifurcation