self-sacrifice n.

Old English self, sylf (West Saxon),  seolf (Anglian), "one's own person, -self; own, personal; same, identical," from Proto-Germanic *selbaz (source also of Old Norse sjalfr, Old Frisian self, Dutch zelf, Old High German selb, German selb, selbst, Gothic silba), Proto-Germanic *selbaz "self," from PIE *sel-bho-, suffixed form of root *s(w)e-, pronoun of the third person and reflexive (referring back to the subject of a sentence), also used in forms denoting the speaker's social group, "(we our-)selves" (see idiom).

Its use as the second element in compounded reflexive pronouns (herself, etc.) was in Old English, from the original independent (and inflected) use of self following personal pronouns, as in ic selfa "myself," min selfes "of myself." With a merging of accusative, dative, and genitive cases.

As a noun from c. 1200 as "the person or thing previously specified;" early 14c. as "a person in relation to that same person." G.M. Hopkins used selve as a verb, "become or cause to become a unique self" (1880) but its use seems to have been restricted to poets.

late 13c., "the offering of something (especially a life) to a deity as an act of propitiation, homage, etc.;" mid-14c., "that which is offered (to a deity) in sacrifice," from Old French sacrifise "sacrifice, offering" (12c.), from Latin sacrificium, from sacrificus "performing priestly functions or sacrifices," etymologically "a making sacred," from sacra "sacred rites" (properly neuter plural of sacer "sacred;" see sacred) + combining form of facere "to make, to do" (from PIE root *dhe- "to set, put").

Originally especially of Christ's propitiatory offering of himself for the world. Latin sacrificium is glossed in Old English by ansegdniss. The general sense of "act of giving up a desirable thing for a higher object or to a more pressing claim," also "something given up for the sake of another" is recorded from 1590s. Baseball sense of "hit made by the batter not to get himself to base but to enable another player to advance" is by 1880.