undermargin noun 3verb 2forms 3 noun3 •The lower rim or margin of something.To overcome this difficulty, the undermargins of the poultice may be treated with Some oleaginous material such as petrolatum or one of the vegetable oils. — 1949 •The lower margin of a page or of an inset image on a page, where it is possible to add a caption.On the undermargin stands the inscription: "Abolish the Tsing, exterminate the Manchoos.” — 1866 •A shortfall; the amount by which the value of an investment purchased on margin falls below the required maintenance amount.An undermargin or shortfall in security can occur at any time during a company's business cycle. — 1990 verb2 •To fall below margin; to create an undermargin.Marchisi's account had a negative equity of $492 and was undermargined by $4,534. — 2006 •To buy less on margin than one can afford.Finally, exchanges need to be wary of adverse selection — positions that are undermargined would be heavily used while those that are overmargined would be less popular. — 2010 formsundermargined · undermargining · undermargins