english
1
general::
Phrase(s): tread (up)on someone or something to walk or step on someone or something. (Upon is formal and less commonly used than on. Step is more common than tread.) • Don’t tread on Sam, who is napping under the tree. • Please don’t tread on the freshly shampooed carpeting on the stairs.
McGrawhill's American Idioms And Phrasal Verbs