Slot is a type of Trail. Trail is related to Ridge. Ridge is a type of Cover. Cover is a synonym of Extend. 
Toilet is related to Plunge. Plunge is related to Fall. 
Slot --IsA--> Trail <--RelatedTo--> Ridge --IsA--> Cover <--Synonym--> Extend 
Toilet <--RelatedTo--> Plunge <--RelatedTo--> Fall 