Bit of a strange one :)
Me and my colleague are having a bit of a debate.
I call the 12 o-clockish meal dinner. Always been "dinner ladys" (don't shoot me for being sexist!) at school and dinner time.
And I call my afternoon meal Tea.
My colleague called the 12-oclock meal "lunch" and the afternoon meal dinner.
Maybe its just a northern thing, interested to see what you all think thou.