still waters run deep

Syllable breakdown

Dictionary meaning

a quiet, calm, or reserved exterior manner often conceals great depth of knowledge, feeling, or strength of character beneath the surface; the hydrological observation that slowly moving water in a river is typically deeper than fast, turbulent water is used as a metaphor for the relationship between outward expression and inner depth, suggesting that the most impressive intelligence or the most powerful emotions are not always the ones most loudly or turbulently expressed; the phrase warns against underestimating people who do not draw attention to themselves and counsels attentiveness to those whose apparent calm may mask formidable inner resources