fog1 (fôg, f¼g) n. 1. Condensed water vapor in cloudlike masses lying close to the ground and limiting visibility. 2.a. An obscuring haze, as of atmospheric dust or smoke. b. A mist or film clouding a surface, as of a window, lens, or mirror. 3. A cloud of vaporized liquid, especially a chemical spray used in fighting fires. 4.a. A state of mental vagueness or bewilderment. b. Something that obscures or conceals; a haze: shrouded their actions in a fog of disinformation. 5. A blur on a developed photographic image. --fog v. fogged, fog·ging, fogs. --tr. 1. To cover or envelop with or as if with fog. 2. To cause to be obscured; cloud. 3. To make vague, hazy, or confused: a memory that had been fogged by time. 4. To obscure or dim (a photographic image). --intr. 1. To be covered with or as if with fog. 2. To be blurred, clouded, or obscured: My glasses fogged in the warm air. 3. To be dimmed or obscured. Used of a photographic image. [Perhaps of Scandinavian origin.] --fog“ger n.
fog2 (fôg, f¼g) n. 1. A new growth of grass appearing on a field that has been mowed or grazed. 2. Tall, decaying grass left standing after the cutting or grazing season. [Middle English fogge, tall grass. See pü- below.]
pü-. Important derivatives are: foul, filth, defile1, fuzzy, putrid, potpourri, putrefy, purulent, pus. .
pü-. To rot, decay. 1. Suffixed form *p¿-lo-. a. FOUL, from Old English f¿l, unclean, rotten; b. FULMAR, from Old Norse f¿ll, foul; c. FILTH, from Old English fþlth, foulness, from Germanic abstract noun *f¿lith½; d. FILE3; DEFILE1, from Old English fþlan, to sully, from Germanic denominative *f¿ljan, to soil, dirty. a, b, c, and d all from Germanic *f¿laz, rotten, filthy. 2. Extended form *pug-. FOG2, from Middle English fog, fogge, aftermath grass, from a Scandinavian source probably akin to Icelandic f¿ki, rotten sea grass, and Norwegian fogg, rank grass, from Germanic *fuk-. 3. Extended variant form *pous-. FUZZY, from Low German fussig, spongy, from Germanic *fausa-. 4. Suffixed form *pu-tri-. PUTRESCENT, PUTRID; (OLLA PODRIDA), (POTPOURRI), PUTREFY, from Latin puter (stem putri-), rotten. 5. Suffixed form *puw-os-. a. PURULENT, PUS; SUPPURATE, from Latin p¿s, pus; b. PYO-, from Greek puon, puos, pus. 6. EMPYEMA, from Greek compound empuein, to suppurate (en-, in; see en). [Pokorny 2. pü- 848.]
mist (m¹st) n. 1. A mass of fine droplets of water in the atmosphere near or in contact with the earth. 2. Water vapor condensed on and clouding the appearance of a surface. 3. Fine drops of a liquid, such as water, perfume, or medication, sprayed into the air. 4. A suspension of fine drops of a liquid in a gas. 5. Something that dims or conceals. 6. A haze before the eyes that blurs the vision. 7. Something that produces or gives the impression of dimness or obscurity: the mists of the past. 8. A drink consisting of a liquor served over cracked ice. --mist v. mist·ed, mist·ing, mists. --intr. 1. To be or become obscured or blurred by or as if by mist. 2. To rain in a fine shower. --tr. 1. To conceal or veil as if with mist. 2. To moisturize (plants or dry air, for example) with a fine spray of water. [Middle English, from Old English. See meigh- below.]
meigh-. Important derivatives are: mist, mistletoe.
meigh-. To urinate. 1.a. MIST, from Old English mist, mist; b. MIZZLE1, from Middle English misellen, to drizzle, from a source perhaps akin to Dutch dialectal mieselen, to drizzle; c. (MISSEL THRUSH), MISTLETOE, from Old English mistel, mistletoe, from Germanic diminutive form *mihst-ila-, mistletoe (which is propagated through the droppings of the missel thrush). a, b, and c all from Germanic suffixed form *mih-stu-, urine, hence mist, fine rain. 2. Suffixed form *migh-tu-. MICTURATE, from Latin micturºre, to want to urinate (desiderative of meiere, to urinate). [Pokorny meik- 713.]
Note added at 2 mins (2005-04-07 03:46:33 GMT)
So it appears that there isn\'t much difference at all.