margin call noun 1margin-call verb 1forms 4 noun1 •A request by a stockbroker or similar for a client to deposit more money in order to cover losses that have built up in open positions held on margin (rather than having been paid for in full). margin-call verb1 •To issue a margin call to (someone).Not only was Merrill margin-calling subprime lenders, but it was now margin-calling a subprime hedge fund managed by one of its fiercest competitors. — 2008 formsmargin-called · margin-calling · margin-calls · margin calls