1550s, "severe toil, hard work, drudgery;" from slave (v.) + -ery. The meaning "state of servitude, condition of a slave, entire subjection to the will and commands of another" is from 1570s; the sense of "the keeping or holding of slaves" is from 1728.

"favoring slavery; siding with the political interests of slaveholders," 1825, from pro- + slavery.

"act of enslaving; state of being enslaved, slavery, bondage, servitude," 1690s, from enslave + -ment.

in U.S. history, "opposed to expansion of slavery into the territories," 1846, from free soil (n.) in reference to settled regions without slavery, from free (adj.) + soil (n.). Related: Free-soiler.

"advocacy of immediate action" (originally with reference to abolition of slavery in the U.S.), 1834, from immediate + -ism.

early 15c., earlier servitute (late 14c.), "slavery, bondage, condition of being enslaved," from Old French servitude, servitute (13c.) and directly from Late Latin servitudo "slavery," from Latin servus "a slave" (see serve (v.)) + abstract noun suffix (see -tude). Also "state of being a feudal vassal" (c. 1500). The meaning "compulsory service or labor," such as a criminal undergoes, is by 1828.

Other words in similar senses, many obsolete, include servantship "state or condition of being a servant" (1570s);  servage "servitude, bondage, slavery; serfdom, subjugation, feudal homage to a ruler" (c. 1300, from Old French servage and directly from Medieval Latin servagium); servity "slavery, servitude" (late 15c., from Latin servitus). 

also manstealer, "one who kidnaps human beings to sell into slavery," 1580s, from man (n. ) + agent noun from steal (v.).

"violent aversion to or hatred of Negroes," 1819, in U.S. Congressional debates over admitting slavery into Arkansas Territory, from Negro + -phobia.

"make a slave of, reduce to slavery or bondage," 1640s, from en- (1) "make, make into" + slave (n.). Related: Enslaved; enslaving.

"belief in the principle of abolishing (something)," 1790, in a purely anti-slavery sense (distinguished from opposition to the slave trade); from abolition + -ism.