Obtuse, which comes to us from the Latin word obtusus, meaning "dull" or "blunt," can describe an angle that is not acute or a person who is mentally "dull" or slow of mind. The word has also developed a somewhat controversial sense of "hard to comprehend," probably as a result of confusion with abstruse. This sense of obtuse is well established, and it is now possible to speak of "obtuse language" and "obtuse explanations," as well as "obtuse angles" and "obtuse readers"; however, it may attract some criticism. If you're hesitant about using new meanings of words, you should probably stick with abstruse when you want a word meaning "difficult to understand."
Latin Ties Things Together With Abstruse
Look closely at the following Latin verbs, all of which are derived from the verb "trudere" ("to push"): "extrudere," "intrudere," "obtrudere," "protrudere." Each of these Latin verbs has an English descendant whose meaning involves pushing or thrusting. Another "trudere" offspring, abstrudere, meaning "to push away" or "to conceal," gave English abstrude, meaning "to thrust away." But that verb didn't make it past the 17th century. The "abstrudere" descendant that did survive is "abstruse," an adjective that recalls the meaning of its Latin parent abstrusus, meaning "concealed."
Examples of abstruse in a Sentence
Her subject matter is abstruse.
you're not the only one who finds Einstein's theory of relativity abstruse
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'abstruse.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
borrowed from Latin abstrūsus "concealed, recondite," from past participle of abstrūdere "to conceal," from abs- (variant of ab-ab- before c- and t-) + trūdere "to push, thrust" — more at threat entry 1