/in'veuh looh"sheuhn/ , n.
1. an act or instance of involving or entangling; involvement.
2. the state of being involved.
3. something complicated.
4. Bot. , Zool.
a. a rolling up or folding in upon itself.
b. a part so formed.
5. Biol. retrograde development; degeneration.
6. Physiol. the regressive changes in the body occurring with old age.
7. Gram. a complex construction in which the subject is separated from its predicate by intervening clauses or phrases.
8. Math. a function that is its own inverse.
[ 1605-15; involution- (s. of involutio ). See INVOLUTE, -ION ]