Lewis and Short lists 275 words ending in -mentum, many of which have come into English:

  • argumentum
  • augmentum
  • documentum
  • fragmentum
  • pigmentum
  • segmentum
  • etc.

Wiktionary (cited as an example, not as an authority) says that it is:

derived from the Latin suffix -menta in collective nouns like armenta (“herd, flock”). Latin -menta from Proto-Indo-European -mn̥teh₂ (-mn̥ + *-teh₂).

This confuses me because "collective nouns" hardly seems to describe the majority of these words. I know almost nothing about PIE, so the root words above don't help illuminate the meaning for me.

One pet theory that occurred to me is that perhaps there is a relationship between -mentum and the Greek middle/passive participle ending: -μενον (-menon). It's far-fetched, but works in at least a few cases, e.g. argumentum = quod arguitur, fragmentum = quod frangitur, documentum = quod docetur, etc. (Disclaimer: words selectively chosen to support my theory.)

Can anyone provide an overview of what kinds of words generally use the -mentum suffix, and also comment on whether it adds a predictable meaning to its root word?

  • My understanding was something like "result of ____", somewhat similar to -menon.
    – Draconis
    Commented Mar 27, 2017 at 15:22
  • 3
    To add somewhat to what Draconis has said, my understanding has always been that -mentum shows either instrument (by which the verb that serves as the root is done) or the results of activity (denoted by root). Instrument: a pigmentum is used for painting (pingo), an argumentum is used for proving something (arguo), etc. Result: a fragmentum is the result of breaking (frango), etc.
    – cnread
    Commented Mar 27, 2017 at 17:05
  • 4
    WIktionary's statement makes no sense to me. Weiss (2011:313-4) says "-mentum looks like the neuter substantivization of a possessive derivative in -to- derived from neuters in -men", adducing parallels in Indo-Iranian and Germanic.
    – TKR
    Commented Mar 27, 2017 at 20:30
  • 2
    On the suggested relationship with Gk. -μενος, it's not impossible, but would have to be posited at a "deep" stage of (pre-)PIE, since both the suffixes (-men [n.] and -meno-) already existed in PIE. There are some Latin forms which have been proposed as possibly cognate with -μενος, though: alu-mnus, fē-mina, and the 2pl. pass. ending -minī.
    – TKR
    Commented Mar 27, 2017 at 21:07
  • 3
    I do not have an answer, but it is interesting that many of the words in -mentum have a mostly synonymous counterpart in -men, e. g. fragmen-fragmentum, docimen-documentum. Looks like both these forms coexisted in many cases I just looked up; for one, per L&S, doci/umen was being used by Ter and Lucr and documentum by Cic. Commented Mar 27, 2017 at 23:26

1 Answer 1


According to Miller (2006: 76, 78), the endings -men and -mentum form a deverbal (with one exception) noun with the semantics of means, instrument or result of action of the verb. Relevant quotations are

§3.4 -men [...] ‘means, instrument, result’
While -men is formally and functionally related to -mentum (LG i.§326), the latter will be treated separately for reasons stated in §3.5. [...] Of the two, -men has ceased to be productive since its main function was taken over by -mentum. Most -men derivatives have full grade of the root, but a few have zero grade as well; see -mentum below and Schumacher (2000: 114 f.).

§3.5 -men-tum [...] ‘means, instrument, result’
Historically, -mentum is sometimes considered an enlargement of -men of Indo-European date (LG i.§371). As mentioned in §3.4, numerous doublets existed, such as reg-i-men/reg-i-mentum ‘rule’. Syntactically, however, -mentum shares more with Greek -μα-/-ματ, from <PIE> -mn̥-(-mn̥-t-) (IEL 209), than with L<atin> -men (Sandoz 1994: 328). Apart from rare deadjectivals, such as rudimentum [...] (<from> rudis [...]’), most of the examples are deverbal.

To summarize and provide exact answers to the questions, the ending (I would rather not call it the suffix) -mentum

  1. mostly used to transform verbs, and a few specific adjectives
  2. into a noun capturing the semantic category of either instrument or result of the verb's action.

Speaking of your “pet theory,” I would not call it incorrect right off the bat. While it does not align morphologically with the state of PIE affairs in Latin, it has its merit: your examples quod arguitur, quod frangitur, quod docetur are essentially periphrases for the (missing) middle participle. Then, semantically the Latin paradigm quod X is close enough in its semantics to that of instrument or result of action. This is not so much a straightforward theory, but rather a way of roughly delineating the semantics of the ending -mentum. The quod construct is fuzzier, however: Is quod pingitur something being dyed (more of the passive sense), or something being applied as a dye (more of the middle sense)? Pigmentum is the instrument, an aligns more with the middle sense of the quod construction, while quod pingitur out of context would be less specific.

It is also notable that the doublets that Miller is speaking about (fragmen-fragmentum, documen-documentum, perhaps no less than 100 of these) are not observed of "older" nouns, continuously traced back to the proto-language (such as nomen, germen, semen, stamen, vimen, omen)—there is no e. g. *nomentum. This is a clear illustration of the fact that the ending -mentum was productive in Latin, while -men was not, and many of the -men words were probably back formations from their -mentum counterparts.


Miller, Gary D (2006) Latin Suffixal Derivatives in English and their Indo-European Ancestry. Oxford
LG = Manu Leumann et. al. (1977) Lateinische Grammatik, Munich: Beck.
IEL = Meier-Brugger (2003) Indo-European Linguistics, Walter de Gruyter.

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