micro-

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micro-
1. (μ) From the Greek mikros meaning ‘small’, a prefix meaning ‘extremely small’. Attached to SI units it denotes the unit × 10−6.

2. In Earth sciences, micro- is a prefix applied in the strict sense to very fine igneous textures. Individual particles are likely to be below the resolution of the naked eye so they can be resolved only with the aid of a petrological microscope (see POLARIZING MICROSCOPE). Porphyritic texture which can only be resolved by using such a microscope is termed ‘microporphyritic’ texture and the phenocrysts are ‘microphenocrysts’.

3. The prefix may also be applied to igneous rock names. For example, a syenite with a grain size below that normally accepted for a syenite but above that expected of its fine-grained equivalent, a trachyte, may be termed a microsyenite.

micro-

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micro- • comb. form 1. small: microcar. ∎  of reduced or restricted size: microdot microprocessor.2. (used commonly in units of measurement) denoting a factor of one millionth (10−6): microfarad.

micro-

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micro-, before a vowel micr-, comb. form of Gr. mīkrós, var. of smīkrós small, poss. rel to SMALL; used in many scientific terms. microcosm man viewed as an epitome of the universe. XV. — F. microcosme or medL. mīcro(s) cosmus — Gr. mīkròs kósmos little world. micrometer XVII. — F. micromètre. microphone XVII. microscope XVII.

micro-

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micro-
1. A prefix denoting very small size; e.g. microgamete, micronucleus.

2. Symbol μ. A prefix used in the metric system to denote one millionth. For example, 10–6 metre = 1 micrometre (μm).

micro-

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micro- A prefix meaning ‘small’, from the Greek mikros, meaning ‘small’. Attached to SI units it means the unit × 10−6 (abbreviated as μ).

micro-

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micro- A prefix meaning ‘small’, from the Greek mikros, ‘small’. Attached to SI units it means the unit × 10−6 (abbreviated as μ).