poison pill noun2 •Any strategy designed to produce negative results for an entity carrying out a takeover.There are reasons Twitter may opt not to do a poison pill. It might be wary of potential criticism that a poison pill is deflecting the concerns of a highly vocal member of its community. — 2022 •A provision in a bill that leads to potential supporters opposing it instead."It was a poison pill," Zwonitzer said of the creation of the state military. "We're a landlocked state that does not need an aircraft carrier." — 2012 formspoison pills