PASSION Merriam-Webster Dictionary:
pas•sion /ˈpæʃən/ noun
plural pas•sions
a : a strong feeling of enthusiasm or excitement for something or about doing something
b : something that you enjoy or love doing very much 
c  : a strong feeling of love for something
 As per Wikipedia:
Passion (from the Latin verb patī meaning to suffer) is a term applied to a very strong feeling about a person or thing. Passion is an intense emotion compelling feeling, enthusiasm, or desire for something.
The term is also often applied to a lively or eager interest in or admiration for a proposal, cause, or activity or love – to a feeling of unusual excitement, enthusiasm or compelling emotion, a positive affinity or love, towards a subject.