Possible Clues:

• Watery
• Containing water
• Of water
• Watery area, last two quitting line-up prior to mop-ups from time to time
• Sort of humour watered-down?
• Humour of the eye
• Watery area in France which is beside short river
• Dissolved in water
• Watery build-up in teeth, with front two missing, an endless stream
• Kind of humour found in pupils' surroundings