To put the foot down upon; to walk on or over; to tread on (something that lies in the way); figurative to come suddenly upon (a person or thing)…

transitive. To come upon suddenly or unexpectedly; to catch unprepared.

transitive. ? To startle, come upon suddenly.

(transitive) to attack suddenly.

To move or come as with a spring or sudden bound, to dart. To come or spring suddenly upon (obsolete); to enter with a spring or sudden bound in, into…

to pounce on (or upon). intransitive. Of a person: to spring forward suddenly so as to attack or seize (someone or something). Also in extended uses.

transferred and figurative. Of tears, cries, etc.: To issue suddenly in spite of repressive effort. Of light, sounds, etc.: To issue suddenly from…