supererogatory
英 [,sjuːprə'rɒɡətɔːrɪ]
美 
	    - adj. 额外的,多余的;职责以外的
 
英英释意
- 1. more than is needed, desired, or required;
 - "trying to lose excess weight"
 - "found some extra change lying on the dresser"
 - "yet another book on heraldry might be thought redundant"
 - "skills made redundant by technological advance"
 - "sleeping in the spare room"
 - "supernumerary ornamentation"
 - "it was supererogatory of her to gloat"
 - "delete superfluous (or unnecessary) words"
 - "extra ribs as well as other supernumerary internal parts"
 - "surplus cheese distributed to the needy"