You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: FUNNY HATS 
Clue: The name of this often brimless hat, popular in the 1920s, is French for "bell", after the shape of the hat
a cloche

Category: HOUSEPLANTS 
Clue: Roots sticking through drainage holes in containers are a sign that it's time to do this
re-pot

Category: GEOLOGY 
Clue: This "table" is the saturated area of bedrock; it tends to follow the contours of the land

the water table