Learned borrowing from Late Latinpleroma(“(Gnosticism) spiritual universe seen as the totality of the essence and powers of God”), from Koine Greekπλήρωμᾰ(plḗrōma, “(biblical) perfect fullness”), Ancient Greekπλήρωμᾰ(plḗrōma, “that which fills, a complement; a filling up, a completing”), from πληρόω(plēróō, “to make full, fill; to complete, finish”) (from πλήρης(plḗrēs, “complete, full”) (from Proto-Indo-European*pleh₁-(“to fill”)) + -όω(-óō, suffix forming verbs with the sense of making someone be or do something)) + -μᾰ(-ma, suffix forming nouns denoting the result or effect of an action).[1][2]
Sense 2 (“state of perfect fullness”) is chiefly used in reference to Colossians 2:9 of the Bible: “Ὅτι ἐν αὐτῶῳ κατοικεῖ πᾶν τὸ πλήρωμα τῆς θεότητος σωματικῶς(Hóti en autôōi katoikeî pân tò plḗrōma tês theótētos sōmatikôs) [For in Christ all the fullness of the Deity lives in bodily form]”.[1]
In his [Jakob Eriksson's] investigations of the meristem (the tissue from which the permanent tissues are formed) by dicotyledonous roots he found four types of growth, […] In the second type only two separate meristem tissues are present in the tips of the roots; a pleroma and a common tissue, from which the primary bark and epidermis and root-cap proceed.
[I]n the pleroma of the primary meristem of roots there is not only cambium (persistent parenchyma) and procambium (forerunner of fibres and vessels), but pericambium—i.e., a special outer layer of the plerome that remains for a long time as meristem.
2001, Russian Journal of Developmental Biology: A Journal of Original Papers and Reviews on Developmental and Cell Biology, volume 32, Moscow: Pleiades Publishing, →ISSN, →OCLC, page 205, column 1:
In the pleroma of hyacinth and pea roots, increases along the meristem, especially in its basal part[…].
1697 May 5 (date written; Gregorian calendar), E. W. [i.e., Edward Stillingfleet], “Postscript”, in The Bishop of Worcester’s Answer to Mr. [John] Locke’s Letter, Concerning Some Passages Relating to His Essay of Humane Understanding,[…], London:[…] J. H. for Henry Mortlock[…], published 1697, →OCLC, page 143:
And is all this Cabala too, and only to be uſed when People are to be gulled with noiſy Nothings? i.e. with empty Pleroma's, and ſilent Thunderclaps.
There is a way to comprehend the gnostic's giant onion of a world, the concentric circles, with the Pleroma beckoning there, the white heart of light, the source of that primal vision which for a second or two can recapture paradise.
David Don (1822 November 16) “XXIV.—An Illustration of the Natural Family of Plants called Melastomaceæ.”, in Memoirs of the Wernerian Natural History Society, volume IV, part II, Edinburgh:[…][by P. Neill] for Adam Black,[…]; London:Longman, Hurst, Rees, Orme, & Brown, published 1823, →OCLC, page 295: “Nomen duxi ab voce Græca πληρωμα, plenitudo, quòd loculi capsulæ placentis carnosis seminiferis farcti sunt. ― I took the name from the Greek word πληρωμα, fullness, as the loculi of the capsules are stuffed with fleshy seed-producing cakes.”