softcore (adj.)

Old English softe, earlier sefte, "gentle, mild-natured; easeful, comfortable, calm, undisturbed; luxurious," from West Germanic *samfti, from Proto-Germanic *samftijaz "level, even, smooth, gentle, soft" (source also of Old Saxon safti, Old High German semfti, German sanft; and from a variant form with -ch- for -f-, Middle Dutch sachte, Dutch zacht, German sacht), from PIE root *sem- (1) "one; as one, together with" (the source of seem andsame). The etymological sense would be "smooth and agreeable," to the touch, senses, or mind.

From c. 1200 of persons, hearts, etc., "tender, yielding to emotions," also "easily moved or swayed; soft-hearted, sympathetic; docile." It is attested from late 14c. as "indulgent," also "physically feeble; effeminate, easily overcome, lacking manly courage." The meaning "foolish, simple, silly" is attested from 1620s.

It is attested from mid-13c. of material things, "not stiff, not coarse, fine; yielding readily to pressure." Of sounds or voices, "quiet, not loud or harsh," from early 13c. Of words, "mild, restrained; courteous" mid-14c. From late 14c. of wind, rain, etc.

From 1755 of water ("relatively free from mineral salts"), from 1789 of coal (generally meaning bituminous as opposed to anthractic). In reference to drinks, "non-alcoholic" by 1880. Of letters (-c-, -g-, etc.) when pronounced with more sibilance and less plosiveness, 1630s.

In reference to technology, "using natural resources," by 1974, perhaps 1970. Of a science or methods or data, "not subject to experimental verification, not mathematical," c. 1960.

Many phrases simply are contrasts to earlier ones in hard: Soft landing is from 1958 and the U.S. space program; soft rock as a music style is attested from 1969. Soft spot "weak or vulnerable place," literal and figurative, is by 1933, colloquial. The soft sell sales pitch that relies on gentle persuasions is so called by 1955. Soft-shoe as a dancing style is attested from 1927. The photographic soft-focus (adj.), in reference to camera lenses or shots, is from 1917; figurative use of it is by 1961. The softer sex "women collectively" is from 1640s.

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.

also hard-core; 1936 (n.); 1951 (adj.); from hard (adj.) + core (n.). Original use seems to be among economists and sociologists, in reference to unemployables. Extension to pornography is attested by 1966. Also the name of a surfacing material.