The meaning of sacrifice is to "make holy". But it doesn't mean the disregard of loss. It is a meaningful, determined act of the will.
Sacrifice is the giving up of something of value on one plane of existence for something better on another plane, even the spiritual.
Sacrifice means exchanging something of value on earth, money, promotions, sex, houses ,etc, for integrity, for love, truth, true beauty, virtue.
Sacrifice doesn't mean giving up of something for nothing. It is still an exchange of net gain. To not gain something is foolishness. But not of gain in the eyes of the world but in the eyes of a higher and greater power and being.