in Haeckel's system, biological development of the forms of organisms, 1851; see morpho- + -geny.

"single-rail railway system," 1885, from French; a hybrid; see mono- + rail (n.1).

also decimalisation, "act of reducing to a decimal system" (especially of currency), 1842; see decimal + -ization.

"to rid of the system or qualities of colonialism," by 1955; see  de- + colonial + -ize. Related: Decolonialization.

"system of muscles considered with reference to its origin and development," 1875, from French musculature, from Latin musculus (see muscle (n.)).

1721, in reference to the system of musical notation devised by Guido d'Arezzo, who lived early 11c.

"process of laying roads according to the system of John L. McAdam;" 1824, noun of action from macadamize (see macadam).

the computer operating system by Microsoft was introduced in 1985 and modified thereafter; it was predominant by c. 1995.

"one who devotes himself to the spread of any system of principles," 1797, from propaganda + -ist. Related: Propagandistic; propagandism.

1935; see eco- + system. Perhaps coined by English ecologist Sir Arthur George Tansley (1871-1955).