The Japanese view of life embraced a simple aesthetic
that grew stronger as inessentials were eliminated
and trimmed away.
Wabi stems from the root wa, which refers to harmony, peace, tranquillity, and balance. Generally speaking, wabi had the original meaning of sad, desolate, and lonely, but poetically it has come to mean simple, unmaterialistic, humble by choice, and in tune with nature. Someone who is perfectly herself and never craves to be anything else would be described as wabi. Sixteenth-century tea master Jo-o described a wabi tea man as someone who feels no dissatisfaction even though he owns no Chinese utensils with which to conduct tea. A common phrase used in conjunction with wabi is "the joy of the little monk in his wind-torn robe." A wabi person epitomizes Zen, which is to say, he or she is content with very little; free from greed, indolence, and anger; and understands the wisdom of rocks and grasshoppers.
Taken from http://nobleharbor.com/tea/chado/WhatIsWabi-Sabi.htm