Some three letter words that end with "o" are:
who
too
One three letter word relating to anger and ending with O is ego.
Coo
oaf
ExpressoFalsettoFandango.
bingobravodittohippomottomangopestorodeotango
Some nouns that end with O are:avocadobanjobarriobongobuffalocargoDumboechoEggoegoflamingoGeoGeronimoghettogigolohaloherohoboJellokangaroolassoLOGOmangomojitomottonachoOhioOreopatiophotopianopiccolopotatoradiorhinosolostudiotacotangotattootomatotorpedotriovetovideovolcanoweirdoyo-yozerozoo
Apollo
Arriero
Do, no, so, to
gusto