Definition
Profound is depth used as praise. Literally it meant deep water — the Latin profundus, 'bottomless' — and every modern sense keeps the vertical metaphor: a profound effect reaches further down than a big one; a profound thinker sees below the surface where quick minds skate; a profound silence has no bottom to touch. The word measures not size but penetration: how far beneath the visible something goes.
Examples
- The discovery had a profound effect on how scientists understand memory.
- A profound silence followed the announcement.
- Her lecture was full of profound observations about language and thought.
Synonyms
deep · far-reaching · intense · penetrating · weighty
In TOEFL & IELTS
'A profound effect/impact/influence on' may be the single most useful collocation in exam writing — it upgrades any cause-and-effect sentence. TOEFL vocabulary items pair 'profound' with 'far-reaching'; IELTS examiners reward 'profoundly changed' over 'completely changed'. Keep it for genuinely deep things: a profound snack is a band-7 error.