減號
Minus \Mi"nus\, a. [L. See {Minor}, and cf. {Mis-} pref. from the French.] (Math.) Less; requiring to be subtracted; negative; as, a minus quantity. {Minus sign} (Math.), the sign [-] denoting minus, or less, prefixed to negative quantities, or quantities to be subtracted. See {Negative sign}, under {Negative}.
minus sign n : a sign indicating the operation of subtraction