Boat is related to Engine. Engine is related to Machine. Machine is related to Equipment. 
Pill is related to Health. Health is related to Human. Human is related to Love. Love is related to Passion. 
Boat <--RelatedTo--> Engine <--RelatedTo--> Machine <--RelatedTo--> Equipment 
Pill <--RelatedTo--> Health <--RelatedTo--> Human <--RelatedTo--> Love <--RelatedTo--> Passion 