To walk.
To trample with hooves.
To dance, especially as a professional.
To kick, especially to kick a football a long way downfield with little accuracy.
The tip of a toe of an ungulate such as a horse, ox or deer, strengthened by a thick keratin covering.
The human foot.
Used other than figuratively or idiomatically: see step, on.
to adulterate a drug for the purpose of increasing its bulk, and therefore its profit; to dilute, cut.