Glossary

1 : devoted to religion or to religious duties or exercises
2 : expressing devotion <a devout attitude>
3 a : devoted to an activity, belief, or type of behavior <a devout baseball fan> b : ²EARNEST 1, sincere <gave them devout thanks>

http://www.wordcentral.com/cgi-bin/student?book=Student&va=devout

I have watched every Cardinals baseball game this year, I am totally devout.