1540s, "structure of any kind," from Middle French machine "device, contrivance," from Latin machina "machine, engine, military machine; device, trick; instrument" (source also of Spanish maquina, Italian macchina), from Greek makhana, Doric variant of Attic mēkhanē "device, tool, machine;" also "contrivance, cunning," traditionally (Watkins) from PIE *magh-ana- "that which enables," from root *magh- "to be able, have power." But Beekes, on formal grounds, objects to the connection to words in Germanic and Slavic. He finds the Greek word isolated and is convinced that it is Pre-Greek.
Main modern sense of "device made of moving parts for applying mechanical power" (1670s) probably grew out of mid-17c. senses of "apparatus, appliance" and "military siege-tower." It gradually came to be applied to an apparatus that works without the strength or skill of the workman.
From 17c.-19c. also "a vehicle; a stage- or mail-coach; a ship," and, from 1901, "a motor-car." Also in late 19c. slang the word was used for both "penis" and "vagina," one of the few so honored.
The political sense "a strict organization of the working members of a political party to secure a predominating influence for themselves and their associates" is U.S. slang, attested by 1876. Machine age, a time notable for the extensive use of mechanical devices, is attested by 1882, though there is this:
The idea of remodelling society at public meetings is one of the least reasonable which ever entered the mind of an agitator: and the notion that the relations of the sexes can be re-arranged and finally disposed of by preamble and resolution, is one of the latest, as it should have been the last, vagary of a machine age. ["The Literary World," Nov. 1, 1851]
Machine for living(in) "house" translates Le Corbusier's machine à habiter (1923).
"unfounded belief that one is sick," by 1816; a narrowing from the earlier sense "depression or melancholy without real cause" (1660s); from Middle English medical term ipocondrie "lateral regions of the upper abdomen" (late 14c.). This is from Late Latin hypochondria, from Greek hypokhondria (neuter plural of hypokhondrios), from hypo- "under" (see hypo-) + khondros "cartilage" (in this case, of the false ribs); see chondro-.
The sense "morbid melancholy" reflects the ancient belief that the viscera of the hypochondria (liver, gall bladder, spleen) were the seat of melancholy and the source of the vapors that caused such feelings. The attempt to put it on a scientific bases passes through hypochondriasis. Also see hype (n.). The poet Cowper is an oft-cited example in late 18c. literature. The focus of sense on the particular symptom "unfounded belief that one is sick" seems to begin 1790s with William Cullen, M.D., professor of physic in the University of Edinburgh, who made a specialty of the topic:
A languor, listlessness, or want of resolution and activity, with respect to all undertakings; a disposition to seriousness, sadness, and timidity; as to all future events, an apprehension of the worst or most unhappy state of them; and, therefore, often upon slight grounds an apprehension of great evil. Such persons are particularly attentive to the state of their own health, to every the smallest change of feeling in their bodies; and from any unusual sensation, perhaps of the slightest kind, they apprehend great danger, and even death itself. In respect to these feelings and fears, there is commonly the most obstinate belief and persuasion. [Cullen, "First Lines of the Practice of Physic," Edinburgh, 1791]
Though to Cullen the clinical definition of hypochondria also included physical symptoms and pains as well as these mental delusions. As the old medical beliefs faded, the word dropped from clinical use but remained in popular use for "groundless morbid fear for one's health." In the 1830s hypochondria could mean merely "morbid melancholy," also "apprehension of evil respecting health, without sufficient cause," and "upper abdomen."