Old English dryge, from Proto-Germanic *draugiz (cf. Middle Low German dröge, Middle Dutch druge, Dutch droog, Old High German trucchon, German trocken, Old Norse draugr), from PIE *dreug-.
Meaning "barren" is mid-14c. Of humor or jests, early 15c. (implied in dryly); as "uninteresting, tedious" from 1620s. Of places prohibiting alcoholic drink, 1870 (but dry feast, one at which no liquor is served, is from late 15c.; colloquial dry (n.) "prohibitionist" is 1888, American English). Dry goods (1708) were those measured out in dry, not liquid, measure. Dry land (that not under the sea) is from early 13c. Dry run is from 1940s.
Old English drygan, related to dry (adj.). Related: Dried; drying. Of the two agent noun spellings, drier is the older (1520s), while dryer (1874) was first used of machines. Dry out in the drug addiction sense is from 1967. Dry up "stop talking" is 1853.
(also wet behind the ears and still wet behind the ears) Not mature; inexperienced; callow: He's not dry behind the ears yet, but he's learning
[entry form 1939+, wet 1931+; perhaps an allusion to the wet condition of newborns]
A person who favors the prohibition of alcoholic drink (1888+)