municipalyoudaoicibaDictYouDict
municipal: [16] Latin mūnus meant ‘office, duty, gift’. Combined with -ceps ‘taker’ (a derivative of the verb capere ‘take’, source of English capture) it formed mūniceps, which denoted a ‘citizen of a Roman city (known as a mūnicipium) whose inhabitants had Roman citizenship but could not be magistrates’. From mūnicipium was derived the adjective mūnicipālis, source of English municipal; this was originally used for ‘of the internal affairs of a state, domestic’, and the modern application to the sphere of local government did not emerge strongly until the 19th century.

The stem of Latin mūnus also crops up in commūnis (source of English common), and so community and municipality are etymologically related. Mūnus in the later sense ‘gift’ formed the basis of the Latin adjective mūnificus ‘giving gifts’, hence ‘generous’, from which ultimately English gets munificent [16].
=> capture, common
civil (adj.)youdaoicibaDictYouDict
late 14c., "relating to civil law or life; pertaining to the internal affairs of a state," from Old French civil "civil, relating to civil law" (13c.) and directly from Latin civilis "relating to a citizen, relating to public life, befitting a citizen," hence by extension "popular, affable, courteous;" alternative adjectival derivation of civis "townsman" (see city).

The sense of "polite" was in classical Latin, from the courteous manners of citizens, as opposed to those of soldiers. But English did not pick up this nuance of the word until late 16c. "Courteous is thus more commonly said of superiors, civil of inferiors, since it implies or suggests the possibility of incivility or rudeness" [OED]. Civil case (as opposed to criminal) is recorded from 1610s. Civil liberty is by 1640s. Civil service is from 1772, originally in reference to the East India Company.
interior (adj.)youdaoicibaDictYouDict
late 15c., from Middle French intérieur and directly from Latin interior "inner, interior, middle," comparative adjective of inter "within" (see inter-). Meaning "of the interior parts of a country" is from 1777; meaning "internal affairs of a country or state" (as in U.S. Department of the Interior) is from 1838. Interior decoration first attested 1807. Interior design from 1927.