c. 1600, from Medieval Latin insubstantialis "not substantial," from in- "not" (see in- (1)) + Late Latin substantialis "having substance or reality, material," in Late Latin "pertaining to the substance or essence," from substantia "being, essence, material" (see substance). Related: Insubstantially.
1827, from insubstantial + -ity.
also aërial, c. 1600, "pertaining to the air," from Latin aerius "airy, aerial, lofty, high" (from Greek aerios "of the air, pertaining to air," from aēr "air;" see air (n.1)). With adjectival suffix -al (1). Also in English "consisting of air," hence, figuratively, "of a light and graceful beauty; insubstantial" (c. 1600). From 1915 as "by means of aircraft." From the Latin collateral form aereus comes the alternative English spelling aereal.
type of confection, 1895, American English, apparently a word first used among students at women's colleges; perhaps a special use from fudge (v.) or its noun derivative, via the notion of "insubstantial" or of something "faked-up" on the spot. The verb was used in school slang, and compare fudge (n.) "a made-up story" (1797).
'He lies,' answered Lord Etherington, 'so far as he pretends I know of such papers. I consider the whole story as froth — foam, fudge, or whatever is most unsubstantial. ...' [Scott, "St. Ronan's Well," 1823]
late 13c., gingerbrar, "preserved ginger," from Old French ginginbrat "ginger preserve," from Medieval Latin gingimbratus "gingered," from gingiber (see ginger). The ending changed by folk etymology to -brede "bread," a formation attested by mid-14c. Meaning "sweet cake spiced with ginger" is from 15c. Figurative use, indicating anything considered showy and insubstantial, is from c. 1600. Sense of "fussy decoration on a house" is first recorded 1757; gingerbread-work (1748) was a sailor's term for carved decoration on a ship. Gingerbread-man as a confection is from 1850; the rhyme ("The Chase of the Gingerbread Man," by Ella M. White) is from 1898.
early 14c., "flat, smooth, sleek; hairless," originally northern according to OED and probably from a Scandinavian source akin to Old Norse slettr "smooth, sleek," from Proto-Germanic *slikhtaz "slippery; flat, level, plain" (source also of Old Saxon slicht; Old Frisian sliucht, Low German slicht "smooth, plain common;" Old English -sliht "level," attested in eorðslihtes "level with the ground;" Old Frisian sliucht "smooth, slight," Middle Dutch sleht "even, plain," Old High German sleht, Gothic slaihts "smooth"), probably from a collateral form of PIE *sleig- "to smooth, glide, be muddy," from root *(s)lei- "slimy" (see slime (n.), and compare slick (v.)).
The original sense is obsolete. The evolution probably is from "smooth" (c. 1300), to "slim, slender; of light texture," hence "not good or strong; insubstantial, trifling, inferior, insignificant" (early 14c.). The meaning "small in amount" is from 1520s.
The sense of German cognate schlecht developed from "smooth, plain, simple" to "bad, mean, base," and as it did it was replaced in the original senses by schlicht, a back-formation from schlichten "to smooth, to plane," a derivative of schlecht in the old sense [Klein]. English slight also had the same tendency, and 15c.-17c., used of persons, could mean "humble, low; of little worth or account."