Ablaut.
A sequence that alternates between positive and negative values; sometimes incorrectly used to mean permutation.
A type of partial truncation of a polygon, polyhedron or tiling in which alternate vertices are removed.
The response of the congregation speaking alternately with the minister.
A construct in a regular expression that can match any of several specified subexpressions.
A pattern by which more than one construct is possible, as with "Alice cooked Bob dinner" and "Alice cooked dinner for Bob".
The reciprocal succession of (normally two) things in time or place; the act of following and being followed by turns; alternate succession, performance, or occurrence
The "inclusive or" truth function.
The quality of being unstable.
A state that is not in equilibrium, or in which a small change has a large irreversible effect.