Get something solid inside (3)
I believe the answer is:
eat
'get' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for eat that I've seen before include "and 27: Be humiliated" , "tolerate in diet" , "Ingest" , "Consume for tea" , "Consume (food)" .)