+

plus (n.)

1570s, the oral rendering of the arithmetical sign +, from Latin plus "more, in greater number, more often" (comparative of multus "much"), altered (by influence of minus) from *pleos, from PIE *pele- (1) "to fill" (see poly-). As a preposition, between two numbers to indicate addition, from 1660s. [Barnhart writes that this sense "did not exist in Latin and probably originated in commercial language of the Middle Ages."] Placed after a whole number to indicate "and a little more," it is attested from 1902. As a conjunction, "and," it is American English colloquial, attested from 1968. As a noun meaning "an advantage" from 1791. Plus fours (1921) were four inches longer in the leg than standard knickerbockers, to produce an overhang, originally a style associated with golfers. The plus sign itself has been well-known since at least late 15c. and is perhaps an abbreviation of Latin et (see et cetera).

Fill...

 

poly-

word-forming element meaning "many, much, multi-, one or more," from Greek poly-, combining form of polys "much" (plural polloi); cognate with Latin plus, from PIE root *pele- (1) "to fill," with derivatives referring to multitudinousness or abundance (cognates: Sanskrit purvi "much," prayah "mostly;" Avestan perena-, Old Persian paru "much;" Greek plethos "people, multitude, great number," polys "much, plenty," ploutos "wealth;" Lithuanian pilus "full, abundant;" Old Church Slavonic plunu; Gothic filu "much," Old Norse fjöl-, Old English fela, feola "much, many;" Old English folgian; Old Irish lan, Welsh llawn "full;" Old Irish il, Welsh elu "much"); probably related to root *pele- (2) "to spread."

Pilus:)

Plius.

Plus.

Plas:)

Pliusas...

1600 BC marble sacral cross from the Temple Repositories of Knossos. (Heraclion Archaeological Museum, Greece)