IPA: /ˈɪnsaɪtfl/
KK: /ˈɪnˌsaɪt̬.fəl/
Having a deep understanding or perception of something; able to see and understand things clearly and intelligently.
Her insightful comments during the discussion helped everyone see the issue from a new perspective.
Insightful → It is formed from "in-" (meaning into) and "sight" (from Old English "siht", meaning vision or seeing) and the suffix "-ful" (meaning full of). The word "insightful" means full of insight or having a deep understanding of something.
Think of 'sight' as vision and 'in-' as going into something — so 'insightful' means going deep into understanding.