1. 
   Oap
   In Enochian, Oap is a cacodemon.
   Found op http://www.probertencyclopaedia.com/browse/DA.HTM
   
   
2. 
   OAP
   Outside Awareness Port
   Found op http://foldoc.org/OAP
   
   
3. 
   OAP
   Over-The-Air Programming - changing the characteristics of a mobile via an OTA function.
   Found op http://www.encyclo.co.uk/visitor-contributions.php
   
   
4. 
   oap
   1) Cacodemon
   Found op http://www.mijnwoordenboek.nl/EN/crossword-dictionary/oap/1
   
   

Tip: double click on a word to show its meaning.