It might seem meagre at first but you'll find it's actually quite substantial (5)
I believe the answer is:
great
'substantial' is the definition.
(thesaurus)
'it might seem meagre at first but you'll find it's actually quite' is the wordplay.
'GREAT' is hidden in amongst the letters.
But, I'm unsure how this is indicated.
Can you help me to learn more?
(Other definitions for great that I've seen before include "Large, important" , "Large; fine" , "Huge or outstanding" , "Brunel's third and last steamship" , "Enormous" .)