Tapas is commonly translated as "austerity".  Shari offers two alternative meanings of this term.  Austerity can also mean discipline, which comes from the root word disciple.  As a "disciple" of yoga, tapas is the depth of the commitment and love you have for the practice.  It also represents the inner radiance you carry throughout your day as a result of having done your practice.  Practice clears away the dust that covers that radiance.