Noun : the back of the head. ,the clothes on his back. ,He put his back into the task. ,the back of a hall. ,the back of a chair. ,the back of a jacket. ,The fall broke his back. ,the back of a binder.    From Dictionary.com. 

Verb (used with object) : to back a candidate; to back up a theory with facts. ,to back a horse in the race. ,to back a car. ,to back a book. ,a beach backed by hills. ,a singer backed by piano and bass.    From Dictionary.com. 

Adjective : at the back door; back fence. ,back settlements. ,back files; back issues. ,back pay. ,back current.    From Dictionary.com.