collection

1. (music) A set of pitch classes used by a composer.Examples: "The "collectional information" one receives is ambiguous since the collection { C, E, F, G, A } occurs in the key of C and in the key of F."; "In fact, students are often taught that specific collections—diatonic, octatonic, and whole-tone, etc.—typify these composers' compositional language."; "Simply put, the realm of available collections in a largely diatonic environment is much smaller than it is in truly atonal one."countableuncountable

2. (set theory, topology, mathematical analysis) A set of sets; used because such a thing is in general too large to comply with the formal definition of a set.countableuncountable

3. (law) Debt collection.countableuncountable

4. (obsolete) The act of inferring or concluding from premises or observed facts; also, that which is inferred.Examples: "We may safely say thus, that wrong collections have been hitherto made out of those words by modern divines."countableobsoleteuncountable

5. (UK) The jurisdiction of a collector of excise.UKcountableuncountable

6. (Oxford University, usually in the plural) A set of college exams generally taken at the start of the term.countableplural-normallyuncountable