Nuclear
mid 19th century: from nucleus + -ar1.
wiktionary
From Latin nū̆cleus, a contraction of the adjective nuculeus, masculine of feminine nuculea(“pertaining to a small nut”) from nucula + adjectival suffix -eus, -ea, -eum. The Latin nucula + -āris adds up to nuculāris, a term that in English becomes nucular; the Latin nuculea + -āris, becomes Latin nuculeāris(“relative to what pertains to small nut”), later contracted into nuclear. Compare muscle and Latin mūsculus; muscular and mūsculāris.
etymonline
nuclear (adj.)
1841, "of or like the nucleus of a cell," from nucleus + -ar, probably by influence of French nucléaire. General sense of "central" is from 1912. In atomic physics, "of or belonging to the nucleus of an atom," from 1914; of weapons deriving their destructive power from nuclear reactions, by 1945.
Hence nuclear energy (1930), nuclear physics (1933), nuclear war (1954). Nuclear winter was coined by U.S. atmospheric scientist Richard Turco but is first attested in article by Carl Sagan in "Parade" magazine, Oct. 30, 1983. Nuclear family, originally a sociologists' term, is first attested 1949 in "Social Structure," by American anthropologist G.P. Murdock (1897-1985). Alternative adjective nucleal is recorded from 1840, probably from French.
