abbreviation

noun

1. The result of shortening or reducing; abridgment.
2. A shortened or contracted form of a word or phrase, used to represent the whole, utilizing omission of letters, and sometimes substitution of letters, or duplication of initial letters to signify plurality, including signs such as +, =, @.
3. The process of abbreviating.
4. A notation used in music score to denote a direction, as pp or mf.