open-ended

[ oh-puh n-en-did ]

/ ˈoʊ pənˈɛn dɪd /

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

First recorded in 1815–25; open + end¹ + -ed³

o·pen-end·ed·ness, noun

Major General Jean Kahwaji of the Lebanese armed forces recently declared an “open-ended war” with the militants.

A Sunni-Shia Love Story Imperiled by al Qaeda |Ruth Michaelson |December 26, 2014 |DAILY BEAST
But the option of replacing a new diplomatic breakthrough with open-ended diplomatic muddle-through is not on the table.

Iran Nuke Deal: A Matter of War or Peace |Christopher Dickey |November 23, 2014 |DAILY BEAST
After any number of open-ended interviews are conducted, a suspect may emerge.

The Myth of the Central Park Five |Edward Conlon |October 19, 2014 |DAILY BEAST
However, even they are now beginning to worry about the long-term effects if these open-ended protests continue.

Hong Kong Between Calm and Chaos |Ben Leung |October 3, 2014 |DAILY BEAST

After several broken agreements, the open-ended ceasefire agreed to on August 26 has held.

The Gaza Strip Before And After |Brandy Zadrozny |September 19, 2014 |DAILY BEAST
The cooks worked in an open-ended extension at the rear of the great room.

On Canada's Frontier |Julian Ralph
That is, they are open-ended connections in status nascendi.

The Civilization of Illiteracy |Mihai Nadin
This is built of open-ended sections jointed so that they may pass round the terminal rollers.

The Romance of Modern Mechanism |Archibald Williams

open-ended

without definite limits, as of duration or amount an open-ended contract

denoting a question, esp one on a questionnaire, that cannot be answered "yes", "no", or "don't know"