Wordnet 3.0
NOUN (1)
1. 
 a device that transfers power from an engine (as in a tractor or other motor vehicle) to another piece of equipment (as to a pump or jackhammer); 
[syn: power takeoff, PTO]
WordNet (r) 3.0 (2006):
PTO
    n 1: a device that transfers power from an engine (as in a
         tractor or other motor vehicle) to another piece of
         equipment (as to a pump or jackhammer) [syn: power
         takeoff, PTO]
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
PTO
       Patent and Trademark Office (org., USA)