1765, from French tontine, named for Lorenzo Tonti, Neapolitan banker in Paris who in 1653 first proposed this method of raising money in France.
"contraceptive sheath," 1706, traditionally named for a British physician during reign of Charles II (a story traceable to 1709), but there is no evidence for that. Also spelled condam, quondam, which suggests it may be from Italian guantone, from guanto "a glove." A word omitted in the original OED (c. 1890) and not used openly in the U.S. and not advertised in mass media until the November 1986 speech by Surgeon General C. Everett Koop on AIDS prevention. Compare prophylactic.
c. 1400, pille, "globular or ovoid mass of medicinal substance of a size convenient for swallowing," from Middle Dutch or Middle Low German pille and Old French pile, all from Latin pilula "pill," literally "little ball," diminutive of pila "a ball, playing ball," which is perhaps related to pilus "hair" if the original notion was "hairball."
The figurative sense "something disagreeable that must be accepted ('swallowed')" is from 1540s. The slang meaning "disagreeable or objectionable person, bore," is by 1871. The pill "contraceptive pill" is from 1957.
As the name of a method of teaching reading by associating letters or groups of letters with particular sounds in an alphabetic writing system, especially as correlations between sound and symbol, it is attested by 1901 and became prominent in that sense after 1950, though the systematic method itself dates from the 1830s.