read in verb 3read-in noun 1forms 3 verb3 •To accept as input.The computer reads in a program file from disk and executes the contents. •To allow access to classified information.― What is this? ― I can tell you what this isn't. This isn't me reading you in, Bernard. •To judicially insert an official legal interpretation into a statute read-in noun1 •(US, historical) A protest in which demonstrators gather in or occupy a segregated library in order to read. formsreading in · reads in · read-ins