Gathering is related to Learn. Learn is the opposite of Forget. Forget is a synonym of Overlook. 
Ladder is a type of Degree. Degree is related to Circle. Circle is a synonym of Orbit. you are likely to find Vacuum in/at/on Orbit. 
Gathering <--RelatedTo--> Learn <--Antonym--> Forget <--Synonym--> Overlook 
Ladder --IsA--> Degree <--RelatedTo--> Circle <--Synonym--> Orbit <--AtLocation-- Vacuum 