1510s, "surgical operation to draw blood by means of a cupping-glass," verbal noun from cup (v.).
There are two modes of cupping: one in which the part is scarified and some blood taken away to relieve congestion or inflammation of internal parts, called wet cupping, or more generally simply cupping; and a second, termed dry cupping, in which there is no scarification no blood is abstracted. [Century Dictionary, 1897]
1894 in the biological sense "repetition of parts in living things;" earlier in rhetoric, "synecdoche in which totality is expressed by contrasting parts" (such as high and low, young and old); from Modern Latin merismus, from Greek merismos "a dividing, division, a partition," from merizein "to divide," from meros "a part, a share" (from PIE root *(s)mer- (2) "to get a share of something"). Related: Meristic. Merismatic "dividing by the formation of internal partitions" is attested by 1849.
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.
1756, "a gradual unfolding, a full working out or disclosure of the details of something;" see develop + -ment. Meaning "the internal process of expanding and growing" is by 1796; sense of "advancement through progressive stages" is by 1836.
Of property, with a sense of "a bringing out of the latent possibilities" for use or profit, from 1885 (Pickering's glossary of Americanisms, 1816, has betterments "The improvements made on new lands, by cultivation, and the erection of buildings, &c."). Meaning "state of economic advancement" is from 1902.
Patterned on Greek engastrimythos, literally "speaking in the belly," which was not originally an entertainer's trick but rather a rumbling sort of internal speech, regarded as a sign of spiritual inspiration or (more usually) demonic possession. Reference to the modern activity so called seems to have begun early 18c., and by 1797 it was being noted that this was a curiously inappropriate word to describe throwing the voice.