What is a teacher?

I know I haven't posted in a while so there are a lot of different things that I have been thinking about over the last few months.  Since I last posted, I have graduated with my Master's degree, finished the school year, started summer work on curriculum and other administrative items, presented at TEPSA about 21st Century Learning and Social and Emotional Learning among other things.  All this change has given time to reflect on what I am doing and why I am doing it.  It has given me the opportunity to reset and recalibrate my educational expectations.

About a month ago I was having a conversation with my wife (or complaining to her would be more accurate) about how as an administrator, I sometimes am not seen as a teacher anymore.  Her response was something like, "well you aren't a teacher anymore."  I got rather defensive when she said this.  Of course I am a teacher.  I may not have my own classroom and students, but that doesn't mean I stopped being a teacher.  My response to her was, "The day I stop being a teacher, is the day I should stop being an administrator."  I mean that too.  One of the problems I feel a lot of school have is that the leadership, whether it is campus leadership or central office, at some point along the way stop being teachers.  They start to view their role as something else, something loosely connected to education.  My first and most important responsibility is ensure that students learn.  That is the job of a teacher.  If I am not doing that as an administrator, then I don't believe I am doing my job.

So I am interested in other people's thoughts.  What is a teacher?  How should we define that?  Where do campus leaders fit in that discussion?