It includes all who have a deep interest in something or some activity.

VOA: special.2009.05.17

Well, crossword puzzles aren't a very deep subject, and we might wonder whether or not we would do better if we were engaged in something more mentally challenging than that.

填字游戏不算很深奥的东西，我们也不知道自己能否做得更好,如果我们去做,比填字游戏更富挑战性的事情。

耶鲁公开课 - 死亡课程节选

It has to do with tapestries and carpets and things like that where you weave different strands in in different ways, and somewhere in my deep recesses I have these words "Wep" And "Warp" Or something like that.

它和挂毯和地毯之类的东西一样,你可以用不同的方式编织不同的线,在我内心深处,有这么一些词,交错,和,蜿蜒

耶鲁公开课 - 聆听音乐课程节选