not having fixed limits; unrestricted; broad: an open-ended discussion.
allowing for future changes, revisions, or additions: open-ended agreements.
having no fixed answer: an open-ended question.
Origin of open-ended
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
without definite limits, as of duration or amountan open-ended contract
denoting a question, esp one on a questionnaire, that cannot be answered "yes", "no", or "don't know"
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Online Etymology Dictionary, © 2010 Douglas Harper