Medical Definition of TISSUE. : an aggregate of cells usually of a particular kind together with their intercellular substance that form one of the structural materials of a plant or an animal and that in animals include connective tissue, epithelium, muscle tissue, and nerve tissue.ull Definition of TISSUE. 1. a: a fine lightweight often sheer fabric. 2. : a piece of soft absorbent tissue paper used especially as a handkerchief or for removing cosmetics.
In mathematics, the adjective constant means non-varying. The noun constant may have two different meanings. It may refer to a fixed and well defined number or other mathematical object. The term mathematical constant (and also physical constant) is sometimes used to distinguish this meaning from the other one. A constant may also refer to a constant function or its value (it is a common usage to identify them).
The absolute value of a number may be thought of as its distance from zero. In mathematics, the absolute value or modulus |x| of a real number x is the non-negative value of x without regard to its sign. Namely, |x| = x for a positive x, |x| = âx for a negative x (in which case âx is positive), and |0| = 0.