Almost all the sources, dictionaries, etc. give a definition that is close to this--reverence, devotion, or adoration offered a divine being. (That, incidentally, is one reason that I included--in the "what not to do in church" discussion--taking the time and care to be properly dressed when attending church. It's a matter of reverence or respect.)
There are some variations in the definition, but it is noteworthy that almost all have a definition that's remarkably close to the others. This, above, is essentially what the word means to me, too.
However, it can be used in a broader sense, and we find that the Bible uses this other approach as well. By this view, acts of charity and obedience that are done as a result of one's commitment to that deity could be called worship, although other sources say that such are consequences of one's worship rather than worship per se. For that reason, what we do in church on Sunday is often termed "Corporate Worship."