The phrase "remains indefinite" is correct and can be used in written English. It is typically used when discussing something that is not changing or has not been determined, and emphasizes the lack of clarity or certainty. Example: The timeline for the construction project remains indefinite, as funding and permits have yet to be secured.
In the meantime I am perfectly happy that the "for now" of "Avenue Q" remains indefinite.
These being the circumstances, there was no full meeting of the delegates of the allied States yesterday, and the time of the presentation of the Note to Turkey remains indefinite.
In addition, in many of stroke studies it remains indefinite about the effect of cerebral infarction on systemic immune organs and subsequent brain secondary damage.
While continuing research on country logistics assessment generates some of this information, its relevance for the decision makers, and relationship to their unpredictability from foreign national logistics systems remains indefinite.
The allegations, according to the government, were made by an outside party, and officials have launched an investigation for a period of time that remains indefinite.
But while Indonesian law requires a minimum of 72 hours between notification and execution, no date has been set, meaning their status remains indefinite.
Mr. Morsi remains under indefinite detention in an undisclosed location with no access to legal counsel.
The Egyptian father of six, falsely convicted in absentia of murder in a mass show trial that has since been discredited in his home country, remains in indefinite secure detention in Australia, despite the inspector general of intelligence and security finding he was not a threat to national security.
The Egyptian father of six, falsely convicted in absentia of murder in a mass show trial that has since been discredited in his home country, remains in indefinite secure detention in Australia by ministerial order, more than a year after the minister's own department chief said he should be considered for a visa.
He remains in indefinite detention, as does Abu Zubaydah, a Saudi citizen alleged to have run terrorist training camps.
Obama made clear at the end of his remarks that indefinite detention remains US policy.
