Nimrod's too old for love and laying it on thick (7)
I believe the answer is:
impasto
But I can't explain it at all! Could you help me understand?
(Other definitions for impasto that I've seen before include "Method of painting" , "application of paint in this way" , "Technique of paint applied thickly" , "Thick-paint technique" , "Technique of laying on paint thickly so that it stands out from a surface" .)