Contraction

Contraction may refer to:

In physiology:

• Muscle contraction, one that occurs when a muscle fiber lengthens or shortens
  • Uterine contraction, contraction of the uterus, such as during childbirth
• Contraction, a stage in wound healing

In linguistics:

• Poetic contraction, the omission of letters in a word for poetic reasons
• Synalepha, merging of two syllables of adjacent words
  • Elision, the loss of a sound
    • Syncope (phonetics), the loss of sounds inside a word
    • Contraction (grammar), the shortening of a word or words by loss of a sound or sounds
  • Synaeresis, the pronunciation of two vowels as a diphthong
  • Crasis, contraction of two vowels into one monophthong

In science:

• Lanthanoid contraction, the decrease in size of the ionic radius of lanthanide elements with their growing atomic number (series of Rare Earth Elements (REE) in the Mendeleev Table)
• The reverse of thermal expansion

In mathematics:

• Contraction mapping, in mathematics, a type of function on a metric space
• Contraction (operator theory)
• Edge contraction or vertex contraction, graph operations used in graph theory
• Tensor contraction in tensor theory
• Contraction (conditional independence), in probability, one of the rules of conditional independence

Other:

• Economic contraction or recession, a reversal of economic growth; the opposite of economic expansion
• A structural rule in proof theory Further information: idempotency of entailment
• In sports, the (sometimes forced) elimination of a team. The opposite of expansion. Example: the elimination of several teams after the Canadian Football League's failed attempt to expand into the United States in the early 1990s.