tread /tred/ verb (past tense trod, past participle trodden)
› [I, T] mainly UK to put your foot on something or to press something down with your foot: I trod on a piece of broken glass. David trod in some paint. The kids were treading cake crumbs into the carpet.
tread carefully/gently/lightly, etc › to be careful what you say so that you do not upset someone
tread water › to float vertically in the water by moving your arms and legs up and down