# Cycle

Cycle, cycles, or cyclic may refer to:

## Anthropology and social sciences

* Cyclic history, a theory of history
* Cyclical theory, a theory of American political history associated with Arthur Schlesinger, Sr.
* Social cycle, various cycles in social sciences
** Business cycle, the downward and upward movement of gross domestic product (GDP) around its ostensible, long-term growth trend

## Arts, entertainment, and media
### Films

* Cycle (2008 film), a Malayalam film
* Cycle (2017 film), a Marathi film

### Literature

* Cycle (magazine), an American motorcycling enthusiast magazine
* Literary cycle, a group of stories focused on common figures

### Music
#### Musical terminology

* Cycle (music), a set of musical pieces that belong together
** Cyclic form, a technique of construction involving multiple sections or movements
** Interval cycle, a collection of pitch classes generated from a sequence of the same interval class
** Song cycle, individually complete songs designed to be performed in a sequence as a unit

#### Albums

* Cycle (album), a 1965 album by the Paul Horn Quintet
* Cycle, a 2003 album by Merzbow
* Cycle, a 2014 album by Buckethead
* Cycles (Cartel album), 2009
* Cycles (David Darling album), 1981
* Cycles (The Doobie Brothers album), 1989
* Cycles (Frank Sinatra album), 1968
* Cycles (Redbone album), 1977
* Cycles, a 2021 album by Sam Teskey

#### Songs

* "Cycles", a 1968 song by Frank Sinatra on his album Cycles
* "Cycles" (song), a 2018 song by Tove Lo
* "Cycle" an interlude by Beck from Morning Phase, 2014

## Science, technology, and mathematics
### Biology

* Cycle (gene), a gene in Drosophila melanogaster that encodes the CYCLE protein
* Cyclic flower, in botany, one way in which flower parts may be arranged
* Menstrual cycle

### Computing

* Cycles, a render engine for the software Blender
* Instruction cycle, the time period during which a computer processes a machine language instruction
* Reference cycle, where a software object refers directly or indirectly to itself

### Mathematics

* Cycle (algebraic topology), a simplicial chain with 0 boundary
* Cycle (graph theory), a nontrivial path in a graph from a node to itself
** Cycle graph, a graph that is itself a cycle
** Cycle matroid, a matroid derived from the cycle structure of a graph
* Cycle (sequence), a sequence with repeating values
** Cycle detection, the algorithmic problem of detecting repetitions in sequences generated by iterated functions
* Cycle, a set equipped with a cyclic order
** Necklace (combinatorics), an equivalence classes of cyclically ordered sequences of symbols modulo certain symmetries
* Cyclic (mathematics), a list of mathematics articles with "cyclic" in the title
* Cyclic group, a group generated by a single element
* Cyclic permutation, a basic permutation (all permutations are products of cycles)

### Other uses in science and technology

* Cycle (angular unit), a unit of plane angle or rotation
* Charge cycle, charging and discharging a rechargeable battery
* Thermodynamic cycle, a sequence of processes that transfer heat and work into and out of a system
* Wave cycle, the repeatable part of a periodic wave
* Cyclic, a primary flight control for helicopters
* Cyclic compound
* Cycle in cycle per second, which is a unit of frequency (rate of repetition)
** A period in alternating current

## Vehicles

* Bicycle
* Motorcycle
* Quadricycle
* Tricycle
* Unicycle

## Other uses

* Cycling, a sport
* Cycle (baseball), a single, double, triple, and home run (in any order) by the same player in one game
* Cycle, North Carolina, a community in the United States