Mural
late Middle English: from French, from Latin muralis, from murus ‘wall’. The adjective was first used in mural crown; later (mid 16th century) the sense ‘placed or executed on a wall’ arose, reflected in the current noun use (dating from the early 20th century).
wiktionary
Borrowed from French mural, from Latin muralis, from murus(“wall”).
etymonline
mural (n.)
painting on a wall, by 1915, short for mural painting "a painting executed upon the wall of a building" (1850), from mural (adj.) "pertaining to a wall or walls" (mid-15c.), from Latin muralis "of a wall," from murus "wall" (Old Latin moiros, moerus), from PIE *mei- (3) "to fix; to build fences or fortifications" (source also of Old English mære "boundary, border, landmark;" Old Norse -mæri "boundary, border-land;" Latin munire "to fortify, protect").
