underwrite [LME] This is first recorded in the literal sense ‘sign at the bottom of a document’, what an insurer would do at the bottom or end of an insurance document. Nowadays the important thing is that they are guaranteeing to pay a certain sum if something is damaged or lost. In business contexts like these, underwrite was probably a direct translation of Latin subscribere ‘to write underneath’, the source of subscribe [LME], which people originally used in the same way.