"optical instrument which by means of a lens or lenses magnifies and renders visible minute objects or details of visible bodies," 1650s, from Modern Latin microscopium, literally "an instrument for viewing what is small;" see micro- + -scope. The dim southern constellation Microscopium was among those introduced by La Caille in 1752.
also nitroglycerin, violently explosive oily light-yellow liquid, 1857, from nitro- + glycerin. So called either because it was obtained by treating glycerine with nitric and sulfuric acids or because it is essentially a nitrate (glyceryl trinitrate). The essential element of dynamite; it is a violent poison when ingested, but in minute doses it is used in the treatment of angina and heart failure.
late 14c., "minute opening, small orifice, or perforation" in the earth, a tree, the body of a human, animal, or insect, a bone, etc.," from Old French pore (14c.) and directly from Latin porus "a pore," from Greek poros "a pore," literally "passage, way," from PIE *poro- "passage, journey," suffixed form of PIE root *per- (2) "to lead, pass over."
mid-15c., in music, "a half-note" (in early medieval music the shortest note used), from Latin minimus "smallest, least; minute, trifling, insignificant;" of time, "least, shortest, very short;" of age, "youngest;" as a noun, "least price, lowest price," superlative of minor "smaller" (from PIE root *mei- (2) "small"). Calligraphy sense "short down-stroke of the pen in making m, n, u, etc." is from c. 1600.
1794, "extremely minute particle," from French molécule (1670s), from Modern Latin molecula, diminutive of Latin moles "mass, barrier" (see mole (n.3)). For ending see -cule. It has a vague meaning at first; the vogue for the word (used until late 18c. only in Latin form) can be traced to the philosophy of Descartes. First used of Modern Latin molecula in modern scientific sense ("smallest part into which a substance can be divided without destroying its chemical character") is by Amedeo Avogadro (1811).
"the eyelashes, hairs which grow from the margins of the eyelid," 1715, from Latin cilia, plural of cilium "eyelid, eyelash," perhaps related to celare "to cover, hide," from PIE root *kel- (1) "to cover, conceal, save," but words for this part of the face can be tricky (see brow). Later extended to one of the minute hair-like processes projecting from a cell or organism (1835). It sometimes is pluralized in English, which is an error. Related: Ciliary; ciliate.
late 14c., "a bit or fragment, small part or division of a whole, minute portion of matter," from Latin particula "little bit or part, grain, jot," diminutive of pars (genitive partis) "a part, piece, division" (from PIE root *pere- (2) "to grant, allot"). In grammar, "a part of speech considered of minor consequence or playing a subordinate part in the construction of a sentence" (1530s). Particle physics, which is concerned with sub-atomic particles, is attested from 1969. In construction, particle board (1957) is so called because it is made from chips and shavings of wood.