Emily Dickinson Lexicon

MUG'GISH, or MUG'GY, a. [W. mwcan, a cloud of fog; mwg, smoke; or from the root of muck.]

1. Moist; damp; moldy; as, muggy straw. Mortimer.
2. Moist; damp; close; warm and unelastic; as, muggy air. [This is the principal use of the word in America.]