(physics) Any of a group of related physical units defined in terms of natural constants.

(physics) Any one of several natural units in a system originally proposed by Max Planck based on universal constants. Symbols for Planck units are the symbol for the physical quantity with a subscript P.

plural of unit interval

(Australia, law) An amount, used as a basis of a penalty fine, which can be adjusted by the government without the need to pass new legislation.

(neurology) A neuron with its associated muscle fibres.

plural of rhythmic unit

plural of monetary unit

(number theory, complex analysis, quaternion theory) An imaginary number (in the case of complex numbers, usually denoted i) that is defined as a solution to the equation i²=-1.

plural of pilosebaceous unit

(linguistics) The shortest grammatically allowable sentence into which a piece of writing can be split.