What does the prefix micro- mean?
Micro- comes from the Greek mikros, which means "small". It shows an extremely small size or, in the metric system, one millionth of a unit.
ESEN
Prefix · very small / one millionth
micro-
Signals extreme smallness or one millionth of a base unit: microscope, microphone, microchip.
Scientific
Written by Bryan López, English teacher · Updated
Micro- in technology and medicine
Micro- is one of the most productive prefixes in science and technology: it appears in devices, in living things you cannot see with the naked eye and in highly precise surgery. In everyday English it also says that something is small in a general sense, or criticizes someone who controls every detail, as in micromanage.
How it is used
Attaches to scientific and technical nouns with no spelling change:
- micro- + instrument/objectscope → microscopephone → microphonechip → microchipwave → microwave
- micro- + field of studybiology → microbiologyorganism → microorganismsurgery → microsurgeryprocessor → microprocessor
Pronunciation: /ˈmaɪkrəʊ/, stressed on the first syllable with a schwa at the end.
How it is pronounced
micro-/ˈmaɪkrəʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
Examples
Root word
With micro-
In a phrase
- scopemicroscopeThe students used a microscope to examine the tissue cells.
- phonemicrophoneShe clipped the microphone to her collar before the speech.
- chipmicrochipMany pet owners microchip their animals in case they get lost.
- wavemicrowaveHe heated the leftovers in the microwave instead of the oven.
- biologymicrobiologyShe specialised in microbiology, studying food-borne bacteria.
- organismmicroorganismThe lab identified the microorganism behind the infection.
- managemicromanageGood managers trust their teams instead of micromanaging them.
Common mistakes
microphone = the device that amplifies your voice
microphone converts sound waves into electrical signals; amplification is the speaker's job
The microphone (microphone) converts sound into an electrical signal. The speaker (loudspeaker) amplifies and reproduces that signal. They are separate components that work together.
micro- always means one millionth in everyday words
micro- means one millionth in scientific measurement but simply "very small" in everyday compound words
In the International System, micro- = 10⁻⁶ (micrometres, microseconds). In everyday compounds like microwave, micromanage, micro-influencer, it simply means "very small" or "small-scale." The context determines which sense applies.
A trick to remember it
Think of a microscope showing tiny things: micro- = small. microscope, microwave.
Practise what you learned
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"The lab identified the ___ responsible for the infection using advanced DNA sequencing."
Exercise 3 · Pick the right one
What does "micromanage" mean in a work context?
Frequently asked questions
What does the prefix micro- mean in English?
The prefix micro- signals extreme smallness or one millionth of a base unit: microscope, microphone, microchip.
How do you pronounce micro-?
The prefix micro- is pronounced /ˈmaɪkrəʊ/. For example, "microscope".
Can you give an example of a word with micro-?
"scope" becomes "microscope". It is a typical example of the micro- prefix.
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