Secular is the opposite of Frequent. Frequent is similar to Common. Common is related to Bread. Bread is related to Base. 
Liver is a type of Organ. Organ is related to Piano. Piano is related to Practice. Practice is related to Custom. 
Secular <--Antonym--> Frequent <--SimilarTo--> Common <--RelatedTo--> Bread <--RelatedTo--> Base 
Liver --IsA--> Organ <--RelatedTo--> Piano <--RelatedTo--> Practice <--RelatedTo--> Custom 