[adjective] recovering readily from adversity, depression, or the like.

The ability to recover quickly from illness, change, or misfortune; buoyancy.

Something that is resilient is strong and not easily damaged by being hit, stretched, or squeezed.

People and things that are resilient are able to recover easily and quickly from unpleasant or damaging events.

Resilience

the resilience of human beings to fight after they’ve been attacked.

References:

http://www.elook.org/dictionary/resilient.html

http://www.answers.com/topic/resilience

http://www.google.com/dictionary?aq=f&langpair=en|en&q=resilient&hl=en