Decline is a synonym of Slope. Slope is the opposite of Ground. you are likely to find Nut in/at/on Ground. Nut is a type of Seed. 
Weight is a type of Artifact. Load is a type of Weight. 
Decline <--Synonym--> Slope <--Antonym--> Ground <--AtLocation-- Nut --IsA--> Seed 
Artifact <--IsA-- Weight <--IsA-- Load 