Which word means difficult to understand?

• A. Infinitesimal
• B. Abstruse
• C. Expiate
• D. Accolade

Answer: (B)

The concept being tested is vocabulary knowledge for describing how easy or hard it is to understand something. The word that means difficult to understand is abstruse. Abstruse is used for ideas, theories, or writings that are so complex, obscure, or highly technical that they require careful study to grasp.

Infinitesimal describes something extremely small, not related to understandability. Expiate means to atone for a wrongdoing, which is about guilt and remedy rather than comprehension. Accolade refers to praise or an award, not anything to do with how understandable something is. So abstruse is the best fit for “difficult to understand.”