INVARIANT
In*va"ri*ant, n. (Math.)
Defn: An invariable quantity; specifically, a function of the coefficients of one or more forms, which remains unaltered, when these undergo suitable linear transformations. J. J. Sylvester.
INVASION
In*va"sion, n. Etym: [L. invasio: cf. F. invasion. See Invade.]
1. The act of invading; the act of encroaching upon the rights or possessions of another; encroachment; trespass.
2. A warlike or hostile entrance into the possessions or domains of another; the incursion of an army for conquest or plunder.
3. The incoming or first attack of anything hurtful or pernicious; as, the invasion of a disease.
Syn. — Invasion, Irruption, Inroad. Invasion is the generic term, denoting a forcible entrance into a foreign country. Incursion signifies a hasty and sudden invasion. Irruption denotes particularly violent invasion. Inroad is entry by some unusual way involving trespass and injury.
INVASIVE
In*va"sive, a. Etym: [LL. invasivus: cf. F. invasif. See Invade.]
Defn: Tending to invade; characterized by invasion; aggressive.
"Invasive war." Hoole.
INVECT
In*vect", v. i.