# abstruse

> English word · Adjective · IPA /əbˈstɹuːs/ · frequency rank #81,076

## Definitions
1. Difficult to comprehend or understand; obscure.
2. Concealed or hidden; secret.

## Etymology
PIE word
 *h₂epó
Learned borrowing from Latin abstrūsus (“concealed, hidden; having been concealed”), an adjective use of the perfect passive participle of abstrūdō (“to conceal, hide; to push or thrust away”), from abs- (from ab- (prefix meaning ‘away; from; away from’)) + trūdō (“to push, shove; to thrust”) (ultimately from Proto-Indo-European *trewd- (“to push; to thrust”)).
Cognates
* Catalan abstrús
* German abstrus (“abstruse”)
* Italian astruso (“abstruse”)
* Middle French abstruse (modern French abstrus, abstruse (“(derogatory, literary) abstruse”)
* Portuguese abstruso (“abstruse”)
* Spanish abstruso (“abstruse”)

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/abstruse