mechanical (adj.)youdaoicibaDictYouDict[mechanical 词源字典]
early 15c., "of or pertaining to machines," from mechanic (adj.) + -al (1); of persons or human actions, "resembling machines, automatic" it is from c. 1600. Related: Mechanically. Mechanical-minded is recorded from 1820.[mechanical etymology, mechanical origin, 英语词源]
sensitive (adj.)youdaoicibaDictYouDict
late 14c., in reference to the body or its parts, "having the function of sensation;" also (early 15c.) "pertaining to the faculty of the soul that receives and analyzes sensory information;" from Old French sensitif "capable of feeling" (13c.) and directly from Medieval Latin sensitivus "capable of sensation," from Latin sensus, past participle of sentire "feel perceive" (see sense (n.)).

Meaning "easily affected" (with reference to mental feelings) first recorded 1816; meaning "having intense physical sensation" is from 1849. Original meaning is preserved in sensitive plant (1630s), which is "mechanically irritable in a higher degree than almost any other plant" [Century Dictionary]. Meaning "involving national security" is recorded from 1953. Related: Sensitively; sensitiveness.
decollate (2)youdaoicibaDictYouDict
"Mechanically separate sheets of paper into different piles", 1960s: from de- 'away from' + collate.
bobsleighyoudaoicibaDictYouDict
"A mechanically steered and braked sledge, typically for two or four people, used for racing down an ice-covered run", Mid 19th century (originally US, denoting a sleigh made of two short sleighs coupled together and used for hauling logs): from bob2 in the sense 'short' + sleigh.
manifoldingyoudaoicibaDictYouDict
"The production of multiple copies of a document, etc., especially mechanically", Late 19th cent.; earliest use found in The Daily News.