deviance n.

c. 1400, deviaunt, "different, deviating, straying, wandering," from Late Latin deviantem (nominative devians), present participle of deviare "turn aside," from Latin phrase de via, from de "off" (see de-) + via "way" (see via). The noun meaning "one that deviates, one who goes astray" is from 1540s. It is attested by 1927 as "something that deviates from normal." In the sexual sense "person whose sexuality deviates from what is held to be normal," from 1952. Also compare deviate (n.), recorded in that sense since 1912.

word-forming element attached to verbs to form abstract nouns of process or fact (convergence from converge), or of state or quality (absence from absent); ultimately from Latin -antia and -entia, which depended on the vowel in the stem word, from PIE *-nt-, adjectival suffix.

Latin present-participle endings for verbs stems in -a- were distinguished from those in -i- and -e-. Hence Modern English protestant, opponent, obedient from Latin protestare, opponere, obedire.

As Old French evolved from Latin, these were leveled to -ance, but later French borrowings from Latin (some of them subsequently passed to English) used the appropriate Latin form of the ending, as did words borrowed by English directly from Latin (diligence,absence).

English thus inherited a confused mass of words from French (crescent/croissant), and further confused it since c. 1500 by restoring -ence selectively in some forms of these words to conform with Latin. Thus dependant, but independence, etc.

late 14c., "a going astray, a turning aside from the (right) way or course, a going wrong, error," from Late Latin deviatus, past participle of deviare "turn aside, turn out of the way," from Latin phrase de via, from de "off, away" (see de-) + via "way" (see via). From 1630s as "departure from a certain standard or rule of conduct or original plan." Statistical sense is from 1858; standard deviation is from 1894. Related: Deviational.