spec

Universal Words noun (BrE) (AmE specs) a detailed description of sth, especially the design and materials needed to produce sth: We want the machine manufactured to our own spec. seealsoSPECIFICATION, SPECS IDIOMS on spec (BrE, informal) when you do sth on spec, you are trying to achieve sth without organizing it in advance, but hoping you will be lucky: I went to the concert on spec-I hadn't reserved a seat. * A lot of young people apply for jobs on spec (= not in reply to an advertisement, but hoping that a job might be available).