overabundant
A four-letter word for cooking fat is "lard".
A four letter word and the opposite of fat would be thin.
fat
skinny
lard
Flab.
Successfully is a 12 letter word with three set of double letters. Stubbornness is another 12 letter word.
Brown recluse is a 12-letter word for a type of spider.
It is thin.
Suet
Meat contains cooking fat.
Lighthearted is a 12 letter word. Lithographed is another 12 letter word that starts with L and ends with D.