in·vo·lu·tion 
(ĭn′və-lshən)
(ĭn′və-lshən)n.
1.
a. The act of involving.
b. The state of being involved.
2. Intricacy; complexity.
3. Something, such as a long grammatical construction, that is intricate or complex.
4. Mathematics An operation, such as negation, which, when applied to itself, returns the original number.
5. Embryology The ingrowth and curling inward of a group of cells, as in the formation of a gastrula from a blastula.
6. Medicine
a. A decrease in size of an organ, as of the uterus following childbirth.
b. A progressive decline or degeneration of normal physiological functioning occurring as a result of the aging process.
[Latin involūtiō, involūtiōn-, from involūtus, past participle of involvere, to enwrap; see INVOLVE.]
in′vo·lution·al adj.
- run (one's) eyes over
- run one's eyes over
- run-on sentence
- run out
- runout
- run out of
- run out of gas
- run out of gas/steam
- run out of steam
- run out on
- run over
- run rings around
- run run out the clock
- run scared
- run short
- run short of
- run (something) up the flagpole
- run something up the flagpole
- runt
- run/take its course
- run through
- run-through
- runtiness
- run to earth
- run to earth/ground