Real Dictionary

twilight
A twilight state or a twilight zone is a situation of confusion or uncertainty, which seems to exist between two different states or categories.
The twilight of a particular period of time is the final stages of it, when the most important events have already happened.
uncountable noun: Twilight is the small amount of light that there is outside just after the sun has gone down.
uncountable noun: Twilight is the time just before night when the daylight has almost gone but when it is not completely dark.

twilight in American English
of or like twilight; dim, obscure, etc.
the subdued light just after sunset or, in less common usage, just before sunrise
adjective: of, pertaining to, or resembling twilight; dim; obscure
noun: the soft, diffused light from the sky when the sun is below the horizon, either from daybreak to sunrise or, more commonly, from sunset to nightfall

twilight in British English
noun: the soft diffused light occurring when the sun is just below the horizon, esp following sunset