Testimony is related to Witness. Catch is a type of Witness. Catch is related to Sail. 
Mere is a synonym of Simple. Simple is related to Bread. you are likely to find Bread in/at/on Dinner. you are likely to find Meat in/at/on Dinner. 
Testimony <--RelatedTo--> Witness <--IsA-- Catch <--RelatedTo--> Sail 
Mere <--Synonym--> Simple <--RelatedTo--> Bread --AtLocation--> Dinner <--AtLocation-- Meat 