Tread is defined as to step on or over or to stay afloat in water.(verb)
See tread in Webster's New World College Dictionary
Origin: ME treden < OE tredan, akin to Ger treten < IE *dreu- < base *drā, to run, step > trap
See tread in American Heritage Dictionary 4
verb trod trod (trŏd), trod·den (trŏdˈn) or trod, tread·ing, treads verb, transitive
Origin: Middle English treden
Origin: , from Old English tredan.
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