combination

UK: /ˌkɒmbɪˈneɪʃ^ən/ US: /ˌkɑmbəˈneɪʃən/ ,(kom′bə nā′shən)

WordReference Random House Learner's Dictionary of American English © 2026

com•bi•na•tion /ˌkɑmbəˈneɪʃən/   n. 

1. [uncountable] the act of combining or the state of being combined.
2. a number of things combined:
   [countable] a combination of ideas.
3. [countable] something formed by combining:
   A chord is a combination of notes.
4. the set of numbers or letters used to open a lock or a safe:
   [countable] He forgot the combination to his locker.

WordReference Random House Unabridged Dictionary of American English © 2026

com•bi•na•tion  (kom′bə nā′shən), n. 

1. the act of combining or the state of being combined.
2. a number of things combined:
   a combination of ideas.
3. something formed by combining:
   A chord is a combination of notes.
4. an alliance of persons or parties:
   a combination in restraint of trade.
5. the set or series of numbers or letters used in setting the mechanism of a combination lock.
6. the parts of the mechanism operated by this.
7. Clothing Often, combinations. a suit of underwear in one piece.
8. Mathematics
   • the arrangement of elements into various groups without regard to their order in the group.
   • a group thus formed. Cf. permutation (def. 1).

• Late Latin combīnātiōn- (stem of combīnātiō), equivalent. to combīnāt(us) combined (see combine, -ate¹) + -iōn- -ion
• Middle French)
• Middle English combinacyoun (1350–1400

com′bi•na′tion•al, adj. 
Synonyms

• 1. association, conjunction, union, coalescence, blending.
• 2. mixture, amalgamation, amalgam.
• 4. association, federation, league, coalition, cartel, combine, monopoly, bloc, cabal, conspiracy.

Collins Concise English Dictionary © HarperCollins Publishers::

combination / ˌkɒmbɪˈneɪʃən/ noun

1. the act of combining or state of being combined
2. a union of separate parts, qualities, etc
3. an alliance of people or parties; group having a common purpose
4. the set of numbers that opens a combination lock
5. a motorcycle with a sidecar attached
6. an arrangement of the numbers, terms, etc, of a set into specified groups without regard to order in the group
7. a group formed in this way. The number of combinations of n objects taken r at a time is n!/[(n – r)!r!]. Symbol: _nC_r
   Compare permutation1
8. the chemical reaction of two or more compounds, usually to form one other compound
9. a tactical manoeuvre involving a sequence of moves and more than one piece

ˌcombiˈnational adjective