insightful

/ɪnˈsaɪt.f(ə)l/adjective

Showing a deep and clear understanding of something.

Example sentence

“Her brief but insightful comments changed the whole discussion.”

A favorite of performance reviews and book blurbs. 'Perceptive' is a slightly older synonym.

Related words

insinuateTo suggest something unpleasant in an indirect way instead of saying it outright.insightA deep look into the inner workings of something; a clear understanding of it, often used with "into".insipidDull and bland; lacking flavor, character, or interest.insidiousCausing damage slowly and secretly, so that it goes unnoticed at first.insolentRude and disrespectful in words or behavior.inscrutableImpossible to understand, read, or interpret.