-cinor

Etymology
From, with vowel weakening in the unstressed syllable and a change to first-conjugation inflectional endings.

The line between suffixes and compounds in Latin is not always clear: some verbs ending in -cinor may be considered to be compounds, but in, the original meaning of is so weakened that -cinor seems to be no more than a suffix.

According to de Vaan, Leumann 1977: 551 follows Ernout in considering the class of verbs ending in -cinor to have arisen by analogical extension from, which is assumed to be a denominal verb derived from a compound noun. Compare also the attested nouns, , , where according to Chase (1900) "the unexplained -cinium seems to have sunk to the force of a suffix".

Alternatively, Chase (1901) and Cocchia (1917) argue that forms in -ōcin- may derive from original -ōnic- (from stems in -ōn- + ) by metathesis, aided by analogy with. Forms in -ōnic- are the source of some Romance derivatives such as, but those forms are usually considered to be the result of, rather than the input to, a process of metathesis.