re·quire / riˈkwīr/ • v. [tr.] need for a particular purpose; depend on for success or survival: three patients required operations. ∎ cause to be necessary: it would have required much research to produce a comprehensive list. ∎ specify as compulsory: the minimum car insurance required by law. ∎ [tr.] (of someone in authority) instruct or expect (someone) to do something: you will be required to attend for cross-examination. ∎ (require something of) regard an action, ability, or quality as due from (someone) by virtue of their position: the care and diligence required of him as a trustee. ∎ wish to have: please indicate how many tickets you require.DERIVATIVES: re·quire·ment n.re·quir·er n.