Deprived driver, e.g., lined up unexpectedly (15)
I believe the answer is:
underprivileged
'deprived' is the definition.
(similar in meaning)
'driver e g lined up unexpectedly' is the wordplay.
'unexpectedly' is an anagram indicator.
'driver'+'e'+'g'+'lined'+'up'='drivereglinedup'
'drivereglinedup' anagrammed gives 'UNDERPRIVILEGED'.
(Other definitions for underprivileged that I've seen before include "In need" , "no advantages" , "Poor" .)