mid-15c., "dregs, any crude mixture of organic matter," from Latin magma "dregs of an ointment," from Greek magma "thick unguent, ointment," from root of massein "to knead, mold," from PIE root *mag- "to knead, fashion, fit." Geological meaning "molten or semi-molten rock" is by 1859. Related: Magmatic.
1660s, cast iron, from iron (n.) + cast (adj.) "made by melting and being left to harden in a mold" (1530s), past-participle adjective from cast (v.) in its sense "to throw something (in a particular way)," c. 1300, especially "form metal into a shape by pouring it molten" (1510s). From 1690s as an adjective, "made of cast-iron;" figurative sense of "inflexible, unyielding" is from 1830.
1550s, originally in mathematics, from converse (adj.). From 1786 as "thing or action that is the exact opposite of another." As an example, Century Dictionary gives "the hollows in a mold in which a medal has been cast are the converse of the parts of the medal in relief." Chaucer has in convers, apparently meaning "on the other side."
"a primitive form, original, or model after which anything is formed," c. 1600, from French prototype (16c.) and directly from Medieval Latin prototypus "original, primitive," from Greek prōtotypon "a first or primitive form," noun use of neuter singular of prōtotypos "original, primitive," from prōtos "first" (see proto-) + typos "impression, mold, pattern" (see type (n.)). In English from 1590s as prototypon.
mid-15c., "to mold or cast from molten metal" (a sense now obsolete), from Latin conflatus, past participle of conflare "to blow up, kindle, light; bring together, compose," also "to melt together," literally "to blow together," from assimilated form of com "with, together" (see con-) + flare "to blow" (from PIE root *bhle- "to blow").
From c. 1600 as "to bring together from various sources." In reference to text, "to form by inadvertent combination of two readings of the same words," from 1885.
1712, "form, shape" (a sense now obsolete), a more classical form of earlier plasm; from Late Latin plasma, from Greek plasma "something molded or created," hence "image, figure; counterfeit, forgery; formed style, affectation," from plassein "to mold," originally "to spread thin," from PIE *plath-yein, from root *pele- (2) "flat; to spread."
Sense of "the liquid part of blood, etc., as distinguished from the corpuscles" is from 1845. In physics, the sense of "ionized gas" is by 1928.
c. 1300, "a throwing," verbal noun from cast (v.). From early 15c. as "the casting of metal, the act or process of founding;" 1788 as "a metal casting, that which has been formed by running molten metal into a mold of a desired form." Theatrical sense is from 1814. Casting couch "divan in a Hollywood casting directors office," with suggestion of sexual favors in exchange for a role in a picture is by 1948.
"viscid fluid secreted by the mucous membranes of animals," 1660s (replacing Middle English mucilage), from Latin mucus "slime, mold, mucus of the nose, snot," from PIE root *meug- "slippery, slimy," with derivatives referring to wet or slimy substances or conditions (source also of Latin emungere "to sneeze out, blow one's nose," mucere "be moldy or musty," Greek myssesthai "to blow the nose," myxa "mucus;" Sanskrit muncati "he releases"). Old English had horh, which may be imitative.
early 14c., "heart or inmost part of anything" (especially an apple, pear, etc.), of uncertain origin, probably from Old French cor, coeur "core of fruit, heart of lettuce," literally "heart," from Latin cor "heart," from PIE root *kerd- "heart."
Meaning "a central portion cut and removed" (as from a tree, soil, etc.) is from 1640s. Meaning "internal mold of a casting, which fills the space intended to be left hollow" is from 1730. Nuclear physics sense "portion of a reactor containing the nuclear fuel and where the reactions take place" is from 1949.