### Clue: Initially placate the French with first-class excuse (4)
### Answer: PLEA 
 ### Explanation: Definition: excuse
  P(initial letter,initially of "placate") + LE(in French, the article "the") **plus**(with) A(the A grade,first-class).
Answer: An excuse,pretext, as in "she declined it on the plea that she had a headache".