1. the property possessed by a sum or total or indefinite quantity of units or individuals;
"he had a number of chores to do"
"the number of parameters is small"
"the figure was about a thousand"
2. a concept of quantity derived from zero and units;
"every number has a unique position in the sequence"
3. a short theatrical performance that is part of a longer program;
"he did his act three times every evening"
"she had a catchy little routine"
"it was one of the best numbers he ever did"
4. a numeral or string of numerals that is used for identification;
"she refused to give them her Social Security number"
5. the number is used in calling a particular telephone;
"he has an unlisted number"
6. a symbol used to represent a number;
"he learned to write the numerals before he went to school"
7. one of a series published periodically;
"she found an old issue of the magazine in her dentist's waitingroom"
8. a select company of people;
"I hope to become one of their number before I die"
9. the grammatical category for the forms of nouns and pronouns and verbs that are used depending on the number of entities involved (singular or dual or plural);
"in English the subject and the verb must agree in number"