underestimate the real value or ability of; "Don't sell your students short--they are just shy and don't show off their knowledge"
sell securities or commodities or foreign currency that is not actually owned by the seller, who hopes to cover (buy back) the sold items at a lower price and thus to earn a profit
the state of inactivity following an interruption; "the negotiations were in arrest"; "held them in check"; "during the halt he got some lunch"; "the momentary stay enabled him to escape the blow"; "he spent the entire stop in his seat"