An excuse for a foreword perhaps (7)
I believe the answer is:
pretext
'an excuse' is the definition.
(a pretext is an excuse or pretence)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for pretext that I've seen before include "False excuse" , "Alleged reason" , "Ostensible justification" , "Excuse, ruse" , "Specious excuse" .)