-plus

Latin

Etymology

From Proto-Italic *-plos, cognate with Ancient Greek -πλόος (-plóos) or -πλός (-plós) (as in διπλός (diplós)), the second element of Old Irish díabul (“double”)^[1] and possibly Proto-Germanic *twīflaz (“doubt”). From an unclear root of the form *pl(H), possibly from Proto-Indo-European *pleh₁- (“to fill”) or Proto-Indo-European *pelh₂- (“to approach”)^[1] or Proto-Indo-European *pel- (“to fold”), source of Proto-Germanic *-falþaz (“-fold”).^[2] Compare also -plex.

Pronunciation

(Classical Latin) IPA^(key): [pɫʊs]
(modern Italianate Ecclesiastical) IPA^(key): [plus]

Suffix

-plus (feminine -pla, neuter -plum); first/second-declension suffix

-times, -fold, suffix used to form proportional numerals

Usage notes

The proportional suffix -plus tends to describe a ratio of size or quantity relative to something else ("so many times as much, so many times as large") and is often used in the neuter singular form as a noun or an adverbial accusative. This proportional suffix is only attested in Classical Latin for a small set of numbers, perhaps only simplus (“simple”), duplus (“twice as much”), triplus (“three times as much”), quadruplus (“four times as much”), octuplus (“eightfold, eight times as much”), and sēscuplus (“one-and-a-half times as much”). It can be found attached to other numbers in postclassical texts, with various analogical alterations in form. For example, aside from -uplus as in octuplus, the suffix can be found in the forms:

-cuplus (from rebracketing of decuplus, possibly also of quīncuplus), as in nōncuplus (“ninefold”), sexcuplus (“sixfold”)
-ecuplus, probably by rebracketing of decuplus, seen in tens (such as vīgecuplus or vīcecuplus (“twentyfold”), quadrāgecuplus (“fortyfold”), octōgecuplus (“eightyfold”), from vīgintī, quadrāgintā, octōgintā), in millecuplus (“thousandfold”), and in nōnecuplus (another variant for "ninefold").

Several numbers show multiple alternative formations. The ordinal numerals seem to have influenced some forms, such as quīntuplus (“fivefold”), sextuplus (“sixfold”), nōnuplus (“ninefold”) from quīntus (“fifth”), sextus (“sixth”), nōnus (“ninth”).

The multiplicative suffix -plex has a similar meaning, but tends to be used adjectivally to describe something composed of or possessing multiple parts.

Declension

First/second-declension adjective.

	masculine	feminine	neuter	masculine	feminine	neuter
	singular			plural
nominative	-plus	-pla	-plum	-plī	-plae	-pla
genitive	-plī	-plae	-plī	-plōrum	-plārum	-plōrum
dative	-plō	-plae	-plō	-plīs
accusative	-plum	-plam	-plum	-plōs	-plās	-pla
ablative	-plō	-plā	-plō	-plīs
vocative	-ple	-pla	-plum	-plī	-plae	-pla

Derived terms

References

↑ ^1.0 ^1.1 De Vaan, Michiel (2008), “-plus”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 475
^ Lucien van Beek (2022), “Chapter 10 The Reflexes of *l̥”, in The Reflexes of Syllabic Liquids in Ancient Greek‎^[1], Leiden, The Netherlands: Brill, →ISBN

[De_Vaan-1] 1.0 ^1.1 De Vaan, Michiel (2008), “-plus”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 475

[2] Lucien van Beek (2022), “Chapter 10 The Reflexes of *l̥”, in The Reflexes of Syllabic Liquids in Ancient Greek‎^[1], Leiden, The Netherlands: Brill, →ISBN

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