ascertainable (adj.)youdaoicibaDictYouDict[ascertainable 词源字典]
1783, from ascertain + -able. Related: Ascertainably.[ascertainable etymology, ascertainable origin, 英语词源]
attainable (adj.)youdaoicibaDictYouDict
1640s; see attain + -able. Related: Attainability.
maintainable (adj.)youdaoicibaDictYouDict
mid-15c., from maintain + -able. Related: Maintainability.
obtainable (adj.)youdaoicibaDictYouDict
1610s, from obtain + -able. Related: Obtainability.
sustainability (n.)youdaoicibaDictYouDict
1907, in reference to a legal objection, from sustainable + -ity. General sense (in economics, agriculture, ecology) by 1972.
Sustainability is defined as a requirement of our generation to manage the resource base such that the average quality of life that we ensure ourselves can potentially be shared by all future generations. ... Development is sustainable if it involves a non-decreasing average quality of life. [Geir B. Asheim, "Sustainability," The World Bank, 1994]
sustainable (adj.)youdaoicibaDictYouDict
1610s, "bearable," from sustain + -able. Attested from 1845 in the sense "defensible;" from 1965 with the meaning "capable of being continued at a certain level." Sustainable growth is recorded from 1965. Related: Sustainably.
unattainable (adj.)youdaoicibaDictYouDict
1660s, from un- (1) "not" + attainable.
unobtainable (adj.)youdaoicibaDictYouDict
1775, from un- (1) "not" + obtainable (adj.). Related: Unobtainability.
unsustainable (adj.)youdaoicibaDictYouDict
1670s, from un- (1) "not" + sustainable (adj.).