A title of respect for a founder of an art. In shotokan, it would be Gichin Funckoshi

Obi                                                                 

Belt

Oi                                                                   

Lunge                                                              

Oi (tsuki, geri uchi, uke etc)                             

Lunge punch, kick, strike, block etc

Oji waza                                                          

To anticipate your opponents attack but counter attack before his attack is complete

Okinawan Te                                                   

The original title of what we call Karate

Okuden                                                           

Secret teachings

Okuri ashi                                                        

Quick leg movements to cover a large distance quickly

Okuri ashi harai                                               

Foot or ankle sweep

Oroshi                                                             

Downward strike or block

Oroshi tsuki, uke                                             

Descending punch or block

Osae                                                               

To press or hold down.

Osae Komi waza                                             

holding down techniques

Osae Uke                                                        

Pressing block

Oshi ateru                                                        

Strike

Osu                                                                 

Greetings, and can also be taken to mean ‘Yes, I understand’

Otoshi                                                             

To drop or sweep

Otoshi empi, uke, tsuki                                    

Dropping elbow, block, punch

Oyo                                                                

Study of techniques in kata, like bunkai but including the follow up techniques

Oyo Waza                                                       

Applications interpreted from techniques in kata, applied according to a given condition