1590s, "move little by little" (intrans.), from inch (n.1). Meaning "drive or force by small degrees" (trans.) is from 1660s. Related: Inched; inching.
"linear measure, one-twelfth of a foot," late Old English ynce, Middle English unche (current spelling c. 1300), from Latin uncia "a twelfth part," from unus "one" (from PIE root *oi-no- "one, unique"). An early Anglo-Saxon borrowing from Latin; not found in other Germanic languages. Transferred and figurative sense of "a very small amount, small quantity" is attested from mid-14c. As the unit of measure of rainfall from 1845. Sometimes misdivided in Middle English as a neynche. Every inch "in every respect" is from early 15c. For phrase give him an inch ... see ell.
"small Scottish island," early 15c., from Gaelic innis (genitive innse) "island," from Celtic *inissi (source also of Old Irish inis, Welsh ynys, Breton enez).
1640s, "pertaining to an ounce," from Latin uncialis "of an inch, of an ounce," from uncia "a twelfth part" (see inch (n.1)). In reference to letters, it is attested from 1712, from Late Latin litterae unciales (Jerome), probably meaning "letters an inch high," from Latin uncialis "of an inch, inch-high." As a noun, "an uncial letter," from 1775.
unit of weight, the twelfth part of a pound, early 14c., from Old French once, unce, a measure of weight or time (12c.), from Latin uncia "one-twelfth part" (of a pound, a foot, etc.), from Latin unus "one" (from PIE root *oi-no- "one, unique"). The Latin word had been adopted in Old English as ynce (see inch).
It was one-twelfth of a pound in the Troy system of weights, but one-sixteenth in avoirdupois. Abbreviation oz. is from older Italian onza. It was used loosely from late 14c. for "a small quantity." Also used in Middle English as a measure of time (7.5 seconds) and length (about 3 inches). In figurative expressions and proverbs, an ounce of X is compared or contrasted with a pound of Y from 1520s.
Proto-Indo-European root meaning "one, unique."
It forms all or part of: a (1) indefinite article; alone; an; Angus; anon; atone; any; eleven; inch (n.1) "linear measure, one-twelfth of a foot;" lone; lonely; non-; none; null; once; one; ounce (n.1) unit of weight; quincunx; triune; unanimous; unary; une; uni-; Uniate; unilateral; uncial; unicorn; union; unique; unison; unite; unity; universal; universe; university; zollverein.
It is the hypothetical source of/evidence for its existence is provided by: Greek oinos "ace (on dice);" Latin unus "one;" Old Persian aivam; Old Church Slavonic -inu, ino-; Lithuanian vienas; Old Irish oin; Breton un "one;" Old English an, German ein, Gothic ains "one."