"medieval chemistry; the supposed science of transmutation of base metals into silver or gold" (involving also the quest for the universal solvent, quintessence, etc.), mid-14c., from Old French alchimie (14c.), alquemie (13c.), from Medieval Latin alkimia, from Arabic al-kimiya, from Greek khemeioa (found c.300 C.E. in a decree of Diocletian against "the old writings of the Egyptians"), all meaning "alchemy," and of uncertain origin.

Perhaps from an old name for Egypt (Khemia, literally "land of black earth," found in Plutarch), or from Greek khymatos "that which is poured out," from khein "to pour," from PIE root *gheu- "to pour" [Watkins, but Klein, citing W. Muss-Arnolt, calls this folk etymology]. The word seems to have elements of both origins.

Mahn ... concludes, after an elaborate investigation, that Gr. khymeia was probably the original, being first applied to pharmaceutical chemistry, which was chiefly concerned with juices or infusions of plants; that the pursuits of the Alexandrian alchemists were a subsequent development of chemical study, and that the notoriety of these may have caused the name of the art to be popularly associated with the ancient name of Egypt. [OED]

The al- is the Arabic definite article, "the." The art and the name were adopted by the Arabs from Alexandrians and entered Europe via Arabic Spain. Alchemy was the "chemistry" of the Middle Ages and early modern times, involving both occult and natural philosophy and practical chemistry and metallurgy. After c. 1600 the strictly scientific sense went with chemistry, and alchemy was left with the sense "pursuit of the transmutation of baser metals into gold, search for the universal solvent and the panacea."

"relating to or produced by alchemy," 1580s; see alchemy + -ical. Related: Alchemistical (1550s); alchemically.

"universal solvent sought by alchemists," 1640s, from French alcahest, from Medieval Latin alcahest, a pseudo-Arabic word coined by Paracelsus (compare alchemy).

1560s, chymist, "alchemist," from French chimiste, from Medieval Latin chimista, reduced from alchimista (see alchemy). The modern spelling is from c. 1790. The meaning "chemical scientist, person versed in chemistry" is from 1620s; the looser meaning "dealer in medicinal drugs" is from 1745, mostly in British English.

1570s, "relating to chemistry, pertaining to the phenomena with which chemistry deals," from chemic "of alchemy" (a worn-down derivative of Medieval Latin alchimicus; see alchemy) + -al (1). In early use also of alchemy. Related: Chemically. Chemical warfare is attested from 1917.

"one who practices or is versed in alchemy," 1510s, from Old French alquemiste, from Medieval Latin alchimista, from Old French alchimie/Medieval Latin alkimia (see alchemy). Also see -ist. Earlier forms were alchemister (late 14c.), alkanamyer (late 15c.), with agent noun suffix -er.

in words from Arabic (or assumed to be), it is the definite article "the." Sometimes rendered in English as el-. Often assimilated to following consonants (as-, az-, ar-, am-, an-, etc.). Examples include almanac, alchemy, alcohol, algebra.

Proto-Indo-European root meaning "to pour, pour a libation."

It forms all or part of: alchemy; chyle; chyme; confound; confuse; diffuse; diffusion; effuse; effusion; effusive; fondant; fondue; font (n.2) "complete set of characters of a particular face and size of type;" found (v.2) "to cast metal;" foundry; funnel; fuse (v.) "to melt, make liquid by heat;" fusible; fusion; futile; futility; geyser; gush; gust (n.) "sudden squall of wind;" gut; infuse; ingot; parenchyma; perfuse; perfusion; profuse; refund; refuse (v.) "reject, disregard, avoid;" refuse (n.) "waste material, trash;" suffuse; suffusion; transfuse; transfusion.

It is the hypothetical source of/evidence for its existence is provided by: Greek khein "to pour," khoane "funnel," khymos "juice;" Latin fundere (past participle fusus) "melt, cast, pour out;" Gothic giutan, Old English geotan "to pour;" Old English guttas (plural) "bowels, entrails;" Old Norse geysa "to gush;" German Gosse "gutter, drain."

also nurseling, "object of a nurse's care, one who is nursed, an infant," 1550s, from nurse (v.) + -ling. Earlier was norseling, in alchemy, "a substance in a preparatory stage" (c. 1500).

"a secret, a mystery," proper singular form of arcana (q.v.); in alchemy, a supposed great secret of nature, hence, generally, "the secret virtue" of anything.