It is best defined as a reaction. The resulting behavior and response a person engages in naturally when experiencing that which can be only described as God.
After receiving the Eucharist, Rick went back into the pew where he was kneeling and was overcome with awe, inner peace, and a powerful surrealism which led him into quiet, personal worship.
Extreme reverence, respect, faith, and devotion dedicated to a deity, pantheon, or philosophy. In the case of people who choose a religion because it makes them feel good about themselves, they themselves are the object of their worship, no matter how ecstatically they utter the name of their deity.
I can't believe that no one else has taken time out from dissing one another's religions or lack thereof to define "worship". But since they haven't, and I can't believe it, I'm sure they worship differently than I do. I wonder if they have time to worship.