"elusive question" is correct and usable in written English.
This phrase refers to a question that is difficult or impossible to answer. For example, "He asked me an elusive question that I couldn't answer."
Whether or the feature has actually increased sales is an elusive question for Mr. Honan and others.
In the process of detailing such feats and their performers, both authors attempt to grapple with the elusive question of the endeavor's legitimacy: Fad or sport?
In Chalcedon bishops devised a formula that was intended to settle, insofar as human language could express the matter, the elusive question of how exactly divinity and humanity came together in Jesus Christ.
Deducing the existence of private rights to sue, a complex area of law in any event, is an even more elusive question in the context in which it reached the Supreme Court in this case.
Till today, the exact mechanism and toxicity of green silver nanoparticles to bacteria is an elusive question.
Perhaps the most elusive question in sports is how one goes about assembling a highly successful team.
Naturally enough, these questions become the focus of speculation in the town, but other, more elusive questions go unanswered.
The humanities, after all, deal with elusive questions of aesthetics, existence and meaning, the words that bring tears or the melody that raises goose bumps.
Experts hope it could offer a window into some of the most pressing and elusive questions in education: Is a collection of superb teachers enough to make a great school?
Britain is spared the embarrassment it suffered last year when a survey of 21 rich countries by Unicef put it bottom of the class; that study included older children and posed elusive questions like "whether children feel loved, cherished and supported, within the family and the community…" That is hard to measure; deaths, diet and schools are fairly easy.
Wis.dm provides a simple yes/no question service which aims to avoid long answers to life's most elusive questions.
