"long, loose outer garment reaching almost to the floor, worn by men or women over other dress," late 13c., from Old French robe "long, loose outer garment" (12c.), from a Germanic source (compare Old High German rouba "vestments"), from West Germanic *raubo "booty" (cognate with Old High German roub "robbery, breakage"), which also yielded rob (v.).
Presumably the notion is of fine garments taken from an enemy as spoil, and the Old French word had a secondary sense of "plunder, booty," while Germanic cognates had both senses; as in Old English reaf "plunder, booty, spoil; garment, armor, vestment."
The meaning "dressing gown" is from 1854; such extended senses often appear first in French, e.g. robe de chambre "dressing gown," robe de nuit "nightgown." From c. 1300 in reference to official vestments and thus indicative of position or membership in a religious order, guild, etc.; metonymic sense of The Robe for "the legal profession" is attested from 1640s.
Middle English pal, from Old English pæll "rich cloth or cloak, purple robe, altar cloth," from Latin pallium "cloak, coverlet, covering," in Tertullian, the garment worn by Christians instead of the Roman toga; related to pallo "robe, cloak," palla "long upper garment of Roman women," perhaps from the root of pellis "skin." The notion of "cloth spread over a coffin" (mid-15c.) led to figurative sense of "dark, gloomy mood" (1742). The earlier figurative sense is "something that covers or conceals" (mid-15c.).
1765, shortened form of mitten (q.v.) in the fashionable sense of "glove without fingers or with very short fingers of black lace or knitted silk, worn by women." In the more general sense of "glove without a separate covering for each finger" by 1812. Baseball sense of "protective glove for a pitcher, catcher, or fielder" is from 1902. Slang sense of "hand" is from 1896. Slang mitt-reader for "fortune teller" is by 1928.