absolute (adj.)youdaoicibaDictYouDict[absolute 词源字典]
late 14c., "unrestricted; complete, perfect;" also "not relative to something else" (mid-15c.), from Middle French absolut (14c., Old French asolu, Modern French absolu), from Latin absolutus, past participle of absolvere "to set free, make separate" (see absolve).

Most of the current senses also were in the Latin word. Sense evolution was "detached, disengaged," thus "perfect, pure." Meaning "despotic" (1610s) is from notion of "absolute in position." Absolute monarchy is recorded from 1735 (absolute king is recorded from 1610s); scientific absolute magnitude (1902), absolute value (1907) are from early 20c. In metaphysics, the absolute "that which is absolute" is from 1809.[absolute etymology, absolute origin, 英语词源]
disengage (v.)youdaoicibaDictYouDict
c. 1600 in figurative sense; 1660s in literal sense of "detach," from dis- "do the opposite of" + engage (q.v.). Related: Disengaged; disengaging.
expeditious (adj.)youdaoicibaDictYouDict
late 15c., expedycius "useful, fitting," from Latin expeditus "disengaged, ready, convenient, prompt; unfettered, unencumbered," past participle of expedire (see expedite). Meaning "speedy, speedily accomplished" is from 1590s. Related: Expeditiously; expeditiousness.
frigate (n.)youdaoicibaDictYouDict
1580s, from Middle French frégate (1520s), from Italian fregata (Neapolitan fregate), which with many names for types of sea vessels is of unknown origin. It is common to the Mediterranean languages (Spanish, Portuguese, Catalan fragata). Originally a small, swift vessel; the word was applied to progressively larger types over the years.
[A] light nimble vessel built for speed; employed in particular for the gleaning of intelligence and the protection and assault of trade-routes. In battle the frigates took station on the disengaged side of the fleet, where they repeated signals, sped on messages, and succoured the distressed. [Sir Geoffrey Callender, "Sea Passages," 1943]
In the old sailing navy usually they carried guns on a raised quarter-deck and forecastle, hence frigate-built (1650s) of a vessel having the quarter-deck and forecastle raised above the main-deck.
neutral (n.)youdaoicibaDictYouDict
mid-15c., "one who remains neutral," from Latin neutralis "of neuter gender," (see neutral (adj.)). Meaning "disengaged position in gear mechanisms" is from 1912.