application programming interface
noun🔊/æplɪˌkeɪʃn ˌprəʊɡræmɪŋ ˈɪntəfeɪs/
🔊/æplɪˌkeɪʃn ˌprəʊɡræmɪŋ ˈɪntərfeɪs/
(abbreviation API)
a set of programming tools that enables a program to communicate with another program or an operating system, and that helps software developers create their own applications (= pieces of software)