complacent /kəmˈpleɪsnt /

▸ adjective showing smug or uncritical satisfaction with oneself or one’s achievements: you can’t afford to be complacent about security. – DERIVATIVES complacently /kəmˈpleɪsntli / adverb.

Complacent and complaisant are two words which are similar in pronunciation and which both come from the Latin verb complacere ‘to please’, but in English they do not mean the same thing. Complacent is far commoner and means ‘smug and self-satisfied’. Complaisant, on the other hand, means ‘willing to please’, as in ‘the local people proved complaisant and cordial’. – ORIGIN mid 17th century (in the sense ‘pleasant’): from Latin complacent- ‘pleasing’, from the verb complacere.

girth /ɡəːθ /

▸ noun 1 [mass noun] the measurement around the middle of something, especially a person’s waist: idle men of great girth an ivy-clad tree of immense girth [count noun] a pike with a girth of 24 inches.

▪ a person’s waist or stomach, especially when large: he tied the knotted towels around his girth. 2 a band attached to a saddle and fastened around a horse’s belly to keep the saddle in place.

▸ verb [with object] archaic surround; encircle: the four seas that girth Britain. – ORIGIN Middle English (in girth (sense 2 of the noun)): from Old Norse gjǫrth.

infidel /ˈɪnfɪd(ɛ)l / derogatory mainly archaic

▸ noun a person who has no religion or whose religion is not that of the majority: a crusade against infidels and heretics (the infidel as plural noun) they wanted to secure the Holy Places from the infidel.

▸ adjective adhering to a religion other than that of the majority: the infidel foe. – ORIGIN late 15th century: from French infidèle or Latin infidelis, from in- ‘not’ + fidelis ‘faithful’ (from fides ‘faith’, related to fidere ‘to trust’). The word originally denoted a person of a religion other than one’s own, specifically a Muslim (to a Christian), a Christian (to a Muslim), or a Gentile (to a Jew).