integer

The word 'integer' entered English in the late 16th century directly from Latin, where 'integer' meant "untouched, whole, complete." This Latin adjective is itself a compound of the negative prefix 'in-' and the root from the verb 'tangere' (to touch). The literal sense of "untouched" evolved metaphorically to mean "whole, unbroken, intact." In mathematics, this concept of wholeness was applied to numbers that are "whole" and not broken into fractional parts, a meaning fully established by the early 17th century. Thus, the journey from the physical idea of being untouched to the abstract numerical concept of completeness is elegantly preserved in the term.

Structure: in (not) + teg (touch) + er (noun suffix) - 'in': Latin prefix meaning "not". - 'teg': From Latin root tangere (to touch), via its past participle stem tact-. - 'er': Latin suffix forming agent nouns or, in this case, a noun denoting a thing with a specific property.