Don't know why dictionary you were reading from Sylvan, or if you read far enough.

From my Webster's New World College Dictionary, Fourth Edition................

.......3 a) to trespass on (private property), esp. for hunting or fishing b) to hunt or catch (game or fish) illegally, esp. by trespassing 4 to take (anything) by unfair or illegal methods; steal --vi.

So it's the illegally part that cinches the deal, covering breaking any game laws such as out-of-season, over limit (even in season), no tag, too small, etc....

Now a humous note - if ever in question as to whether it is poaching - ask a game warden. They usually have pretty good explanations. LOL