☞ micr

micr-
combining form
or micro-1.
  a. small : minute
      microcapsule
  b. used for or involving minute quantities or variations
      microbarograph
2. one millionth (10^-6) part of
    microgram
3.
  a. using microscopy
      microdissection
  : used in microscopy
  b. revealed by or having the structure discernible only by microscopic examination
      microorganism
4. abnormally small
    microcyte
5. of or relating to a small area
    microclimate
6. employed in or connected with microphotographing or microfilming
    microcopy

micr-
combining form
or micro-
Etymology: Middle English micro-, from Latin, from Greek mikr-, mikro-, from mikros, smikros small, short; akin to Old English smēalīc careful, exquisite, Old High German smāhi small, low, Old Norse smār small, and perhaps to Old English smītan to smear — more at smite
1.
 a. : small : minute : petty
  < microcyst >
  — often used to contrast with macr-
 b. : enlarging : magnifying or amplifying — in names of instruments
  < microphone >
  < microscope >
 c. — used for small or minute size, quantities, intensities, or variations
  < microbarograph >
  < microcalorimeter >
  < micrograph >
 d. : minutely
  < microlevel >
2. : one millionth part of (a specified unit)
 < microsecond >
— especially in terms used in the metric system
 < microgram >
and in electricity
 < microfarad >
 < microhm >
3. : microscopic: as
 a. : dealing with, employing, or used in microscopy
  < micropaleontology >
  < microtome >
 b. : revealed by or having its structure discernible only by microscopical examination
  < microfossil >
 c. : prepared for microscopical examination
  < microsection >
4. : abnormally small
 < microdactylous >
— chiefly in nouns denoting a condition of a specified part of the body
 < micrognathia >
5. : of, involving, or for very small or minute quantities of material : on a small or minute scale of chemical operation : microchemical : microanalytical
 < microbalance >
 < microsublimation >
— compare semimicro-, ultramicro-
6. : of very fine grain : in names of rocks
 < microgranite >
7. : of or relating to a small area
 < microclimate >
 < microeconomics >
 < microhabitat >
8. : microphotographed or microfilmed
 < microcopy >
: employed in or relating to microphotographing or microfilming
 < microreader >