Significant is a synonym of Pregnant. Pregnant is similar to Full. Full is related to Crowd. Crowd is related to Chaos. 
you are likely to find Couch in/at/on Apartment. Couch is related to Big. Big is related to Large. Large is related to Boil. 
Significant <--Synonym--> Pregnant <--SimilarTo--> Full <--RelatedTo--> Crowd <--RelatedTo--> Chaos 
Apartment <--AtLocation-- Couch <--RelatedTo--> Big <--RelatedTo--> Large <--RelatedTo--> Boil 