英语词源字典 - 在线词源网站

gas [gas 词源字典]: gas: [17] We get gas from a Flemish pronunciation of Greek kháos ‘chasm, void’ (a derivative of Indo-European *ghəw- ‘hollow’, and source of English chaos [15]). The Flemish chemist J B van Helmont (1577–1644) used the Greek word to denote an occult principal, supposedly an ultra-refined form of water, which he postulated as existing in all matter.

The sound of Greek kh is roughly equivalent of that represented by Dutch and Flemish g, and so the word came to be spelled gas. Its modern application to any indefinitely expanding substance dates from the late 18th century. The derivative gasoline, source of American English gas ‘petrol’, dates from the late 19th century.
=> chaos[gas etymology, gas origin, 英语词源]
clarification (n.): 1610s, "act of clearing or refining" (especially of liquid substances), from French clarification, from Late Latin clarificationem (nominative clarificatio), noun of action from past participle stem of clarificare (see clarify). The meaning "statement revising or expanding an earlier statement but stopping short of a correction" is attested by 1969, originally in newspapers.
expand (v): early 15c., "spread out, open out, spread flat, extend widely;" also transitive, "cause to grow larger;" from Anglo-French espaundre, Old French espandre "spread, spread out, be spilled," and directly from Latin expandere "to spread out, unfold, expand," from ex- "out" (see ex-) + pandere "to spread, stretch" (see pace (n.)). Related: Expanded; expanding.
expansion (n.): 1610s, "anything spread out;" 1640s, "act of expanding," from French expansion, from Late Latin expansionem (nominative expansio) "a spreading out," noun of action from past participle stem of Latin expandere "to spread out" (see expand).