Glowing youngster uniting space and time (7)
I believe the answer is:
lambent
'glowing' is the definition.
(synonyms)
'youngster uniting space and time' is the wordplay.
'youngster' becomes 'lamb' (a lamb is a young sheep).
'uniting space' becomes 'en' (I am not sure about this - if you are sure you should believe this answer much more).
'and' says to put letters next to each other.
'time' becomes 't' (abbreviation).
'lamb'+'en'+'t'='LAMBENT'
Can you help me to learn more?
(Other definitions for lambent that I've seen before include "shedding some light" , "Gleaming with a soft radiance, the moon perhaps" , "Brilliant and light of wit" , "Of flame or light, playing about a surface" , "Glowing with a soft radiance" .)