1: Not blunt instrument - it has point on front (5)

4: Have bananas now (3)

6: To hear's possible in this (7)

7: Partly indicates progress of undergraduate (2,1,6)

10: Lies for each twelve men (7)

12: Backblock not all there (3)

13: Courses finish with Decline and Fall (5)

1: Knock out acrobat's last daring feat (5)

2: Number One in facetiousness (3)

3: Everlasting variety for Peter and Paul (9)

4: ...or stuffed with the alternative (5)

5: Scale Ten after taxes (3)

8: Biting piece of chocolate with dry exterior (5)

9: Irene's new name (5)

10: Plan to return with woman (3)

11: Chatter about some pay-back (3)