micron

UK: /ˈmaɪkrɒn/ US: /ˈmaɪkrɑn/ ,(mī′kron)

Inflections of 'micron' (n):

microns

npl

micra

npl

WordReference Random House Learner's Dictionary of American English © 2025

mi•cron /ˈmaɪkrɑn/   n. [countable] , pl. -crons, -cra /-krə/.  

1. Weights and Measures the millionth part of a meter.

WordReference Random House Unabridged Dictionary of American English © 2025

mi•cron  (mī′kron), n., pl. -crons, -cra (-krə). 

1. Weights and Measures Also called micrometer. the millionth part of a meter. Symbol: μ, mu
2. Chemistry [Physical Chem.] a colloidal particle whose diameter is between 0.2 and 10 microns.
3. [Physics.] a very small unit of pressure, equal to that exerted by a column of mercury 1μ high.

Also, mikron. 

• Greek mīkrón a little, noun, nominal use of neuter singular of mīkrós small; see -on¹
• 1880–85

Collins Concise English Dictionary © HarperCollins Publishers::

micron / ˈmaɪkrɒn/ noun ( -crons, -cra / -krə/)

1. a unit of length equal to 10^–6 metre. It is being replaced by the micrometre, the equivalent SI unit

Etymology: 19th Century: New Latin, from Greek mikros small