O - Big, Large, Major (e.g. ouchigari = major inner reaping).

OBI - Belt.

OKII - Big.

OKURI (v. OKURU) - To send forward (e.g. okurierijime =
sliding lapel neck-lock).

OSAEKOMI - Holding (e.g. osaekomiwaza = holding technique(s)); referee's call signalling to the timekeeper that a hold is effective.

OSHI (v. OSU) - To push.

OTOSHI (v. OTOSU) - To drop (e.g. taiotoshi = body drop).

OWARI - The end.