Related Clues:

• Class act
• What to try to make of this puzzle?
• Loon's lack
• Put through the paces
• Have a gut feeling
• Take it to make the grade
• Measure of skill
• Simpleton's lack
• Brainpower
• Final, e.g.
• Sixth follower
• You need it to make the grade
• Determinant
• Kind of tube or case
• Entrance requirement, sometimes