Dictionary.com
Thesaurus.com
Showing results for infeasible. Search instead for infeasibly.
Synonyms

infeasible

American  
[in-fee-zuh-buhl] / ɪnˈfi zə bəl /

adjective

  1. not feasible; impracticable.


infeasible British  
/ ɪnˈfiːzəbəl /

adjective

  1. a less common word for impracticable

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • infeasibility noun
  • infeasibleness noun

Etymology

Origin of infeasible

First recorded in 1525–35; in- 3 + feasible

Explanation

Infeasible things are impossible, or too complicated to actually be done. Your idea of staging a city-wide game of Capture the Flag is probably infeasible. After several frustrating attempts at walking your cat around the neighborhood on a leash, you might finally decide the idea is infeasible — it's just not going to work the way you imagined. When something is feasible, it's entirely possible. Feasible comes from the Old French faisable, "that may be done," from the Latin root facere, "to make or do." When you add the "not" prefix in-, you get infeasible.

Keep Reading on Vocabulary.com

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The FDA already requires randomized controlled trials prior to approving vaccines and most medicines—except when they would be unethical or infeasible, as is the case for rare diseases and terminal cancers.

From The Wall Street Journal • Dec. 3, 2025

Smith, speaking to The Times, stressed that the new guidelines only apply to situations where the Fire Department has deemed evacuations infeasible.

From Los Angeles Times • Nov. 24, 2025

Electronic tagging can harm whale health, and it is infeasible to continuously monitor more than a small fraction of the population that way.

From Science Daily • Apr. 12, 2024

Gillian Paull, from Frontier Economics, says the increase is likely to be "challenging", as providers face financial strains and difficulty recruiting staff, "but not infeasible".

From BBC • Nov. 16, 2023

Page 71 This is not a line-for-line translation; that the author found infeasible.

From Unwritten Literature of Hawaii The Sacred Songs of the Hula by Emerson, Nathaniel Bright