Like some water cooler cups (5)
I believe the answer is:
conic
'like some water cooler cups' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for conic that I've seen before include "solid, curved" , "With a tapering shape" , "Figure of circle, ellipse, parabola or hyperbola" , "Making point" , "Pointed" .)