chancelloryoudaoicibaDictYouDict[chancellor 词源字典]
chancellor: [11] Etymologically, a chancellor was an attendant or porter who stood at the cancellī, or ‘lattice-work bar’, of a court in Roman times – hence the Latin term cancellārius. Over the centuries the cancellārius’s status rose to court secretary, in due course with certain legal functions. The word came into English, via Anglo-Norman canceler or chanceler, in the time of Edward the Confessor, denoting the king’s official secretary, a post which developed into that of Lord Chancellor, head of the English judiciary.

The court over which he presides, Chancery, gets its name by alteration from Middle English chancellerie, which came from an Old French derivative of chancelier ‘chancellor’. The word’s ultimate source, Latin cancellī ‘cross-bars, lattice, grating’ (a diminutive form of cancer ‘lattice’), came to be applied to the part of a church or other building separated off by such a screen: hence, via Old French, English chancel ‘part of a church containing the altar and choir’ [14].

And a metaphorical application of the notion of a lattice or bars crossing each other has given English cancel [14], via Latin cancellāre and Old French canceller, which originally meant ‘cross something out’.
=> cancel, chancel[chancellor etymology, chancellor origin, 英语词源]
chancellor (n.)youdaoicibaDictYouDict
early 12c., from Old French chancelier (12c.), from Late Latin cancellarius "keeper of the barrier, secretary, usher of a law court," so called because he worked behind a lattice (Latin cancellus) at a basilica or law court (see chancel). In the Roman Empire, a sort of court usher; the post gradually gained importance in the Western kingdoms. A variant form, canceler, existed in Old English, from Old North French, but was replaced by this central French form.