Pocket is a type of Opening. Pocket is a synonym of Pot. Pot is related to Chicken. Chicken is related to Child. 
Era is related to Time. Time is related to Winter. 
Opening <--IsA-- Pocket <--Synonym--> Pot <--RelatedTo--> Chicken <--RelatedTo--> Child 
Era <--RelatedTo--> Time <--RelatedTo--> Winter 