Unknown state car bishop enters (5)
I believe the answer is:
limbo
'unknown state' is the definition.
'limbo' can be an answer for 'state' (limbo is a kind of state). I am not certain of the 'unknown' bit.
'car bishop enters' is the wordplay.
'car' becomes 'limo' (limo is a kind of car).
'bishop' becomes 'B' (chess abbreviation).
'enters' means one lot of letters goes inside another.
'limo' placed around 'b' is 'LIMBO'.
Can you help me to learn more?
(Other definitions for limbo that I've seen before include "nowhere in particular" , "Once supposed abode of the souls of unbaptized infants" , "Unsettled state" , "West Indian dance - state of uncertainty" , "Unresolved state" .)