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Synonyms

abstruse

American  
[ab-stroos] / æbˈstrus /

adjective

  1. hard to understand; recondite; esoteric.

    abstruse theories.

    Synonyms:
    arcane, unfathomable, incomprehensible
    Antonyms:
    obvious, simple, uncomplicated, clear
  2. Obsolete. secret; hidden.


abstruse British  
/ əbˈstruːs /

adjective

  1. not easy to understand; recondite; esoteric

"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

  • abstrusely adverb
  • abstruseness noun

Etymology

Origin of abstruse

1590–1600; < Latin abstrūsus thrust away, concealed (past participle of abstrūdere ), equivalent to abs- abs- + trūd- thrust + -tus past participle suffix

Explanation

Abstruse things are difficult to comprehend because they are deep, complex, and intellectually challenging. While a riddle may be a little tricky to figure out, theoretical quantum entanglement is abstruse. The Latin root of the word abstruse is abstrusus, meaning "hidden, concealed, secret," which is a good way to remember the meaning of this word. It describes something so dense or complex that its meaning feels hidden from understanding. A theory or a text is abstruse when it requires deep study to uncover its "hidden" truth. Some famously abstruse topics include high-level mathematics like Category Theory, "the mathematics of mathematics," and certain coding languages, like Malbolge.

Keep Reading on Vocabulary.com

Vocabulary lists containing abstruse

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.

Mr. Barnes has long brought something exotic to English literature, but never anything so abstruse as to become alienating.

From The Wall Street Journal • Jan. 16, 2026

Also, his estimate arose from abstruse economic formulas and lots of magic asterisks.

From Los Angeles Times • Jul. 8, 2025

The decades-old concept could explain many things, such as where WIMPs come from, but its main job is to solve a more abstruse problem.

From Science Magazine • Mar. 27, 2024

They looked almost comically abstruse, as if they might be used as paddles in the hazing rituals of a math fraternity.

From New York Times • Feb. 8, 2024

Unable to decipher the abstruse writing, I shook my head.

From "Kaffir Boy: An Autobiography" by Mark Mathabane