disposable (adj.)youdaoicibaDictYouDict[disposable 词源字典]
1640s, "that may be done without;" see dispose + -able. Meaning "designed to be discarded after one use" is from 1943, originally of diapers, soon of everything; replaced throw-away (1928) in this sense. First recorded use of disposable income (preserving the older sense) is from 1948.[disposable etymology, disposable origin, 英语词源]
throwaway (adj.)youdaoicibaDictYouDict
also throw-away, 1901 in reference to very low prices; by 1903 in reference to printed material meant to be read once then tossed, and to wasted votes; with reference to disposable consumer goods, attested from 1969. From the verbal phrase, attested from late 14c. in the sense "reject, cast from oneself," from throw (v.) + away (adv.). More literal meaning of "dispose of as useless, release from one's possession as unneeded" is first recorded 1520s. Throw-away society attested from 1967.