from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A tiny particle of meteoric dust, especially one of many that fall to the surface of the earth or moon.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. an extraterrestrial particle, less than a millimeter in size, that has survived entry into the atmosphere without melting
from the GNU version of the Collaborative International Dictionary of English
- n. A meteorite so small that it drifts down to Earth without becoming intensely heated in the earth's atmosphere.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a meteorite or meteoroid so small that it drifts down to earth without becoming intensely heated in the atmosphere
micro- + meteorite (Wiktionary)