Indefinite
Part of speech: adjective
Definition: Without limit; forever, or until further notice; not definite. Vague or unclear. Undecided or uncertain. An integral without specified limits.
Example sentence: Long before, and fully independent of, anything Congress did, President Obama made clear that he was going to preserve the indefinite detention system at Guantanamo even once he closed the camp. President Obama fully embraced indefinite detention - the defining injustice of Guantanamo - as his own policy.
Undefined
Part of speech: adjective
Definition: Lacking a definition or valueThat does not have a meaning and is thus not assigned an interpretation (for example, division by zero)
Example sentence: When the blues came out, it was something pure and undefined, but when all these white groups got hold of it, it became something else that didn't sound anything like the original. So you had Led Zeppelin doing their thing, which had come all the way from the blues.