there are several definitions of the word ARCHITECTURE, but to put it in one sentence, ARCHITECTURE is simply the scientific art of making structure express itself OR an art & science of making building. if i may add to this, it is the most complex art that expresses human feelings.
As everyone is trying to define architecture from his own point of view, i think defining anything means defining LIMITS!
I think this field has NO limits! Becoz it is born with our IMAGINATIONS! either they are possible or impossible! ! !