お
| 御 | お | honorable | |
| 老い | おい | old age, old person, the old, the aged | |
| 追う | おう | to chase, to run after | 939 |
| 追い付く | おいつく | to overtake, to catch up (with) | 1973 |
| 王 | おう | king, ruler, sovereign, monarch | 2113 764 |
| 王様 | おうさま | king | 2113 |
| 王子 | おうじ | prince | 2113 |
| 応じる | おうじる | to respond, to satisfy, to accept, to comply with, to apply for | 2279 |
| 応援 | おうえん | support, assistance | 2279 |
| 横断 | おうだん | crossing | 2280 |
| 横柄 | おうへい | arrogance | 2280 |
| 終 | おわり | the end | 2281 |
| 終る | おわる | to finish, to close | 2281 |
| 終える | おえる | to finish | 2281 |
| 大いに | おおいに | very, much, greatly | 2124 |
| 大家 | たいか | rich family, distinguished family | 2124 |
| おおや | landlord, landlady | ||
| 覆う | おおう | to cover, to hide, to conceal, to wrap, to disguise | 2282 |
| 覆い | おおい | mantel, cover | |
| オーバー | (1) overcoat, (2) over | ||
| 丘 | おか | hill, knoll, rising ground | 2283 1439 |
| 沖 | おき | open sea | 2284 |
| 奥 | おく | interior, inner part | 2285 |
| 贈る | おくる | to send, to give to, to award to, to confer on | 2286 |
| 贈物 | おくりも | present, gift | 2286 |
| 起こる | おこる | to occur, to happen | 747 932 |
| 起きる | おきる | to get up, awaken | 747 932 |
| 幼い | おさない | very young, childish | 1387 |
| 収める | おさめる | to obtain, to reap, to pay, to supply, to accept | 1352 |
| 御祖父さん | おじいさん | grandfather, male senior-citizen | fg71 |
| お喋り | おしゃべり | chattering, talk, idle talk | 705 1607 |
| 汚染 | おせん | pollution, contamination | 2287 |
| 汚水 | おすい | sewage, filthy water | 2287 |
| 恐らく | おそらく | perhaps | 2288 |
| 恐れる | おそれる | to fear, to be afraid of | |
| 恐ろしい | おそろしい | terrible, dreadful | |
| お互い | おたがい | mutual, reciprocal, each other | |
| 穏やか | おだやか | calm, gentle, quiet | 2289 |
| 穏和 | おんわ | mild, gentle | 2289 |
| 男の人 | おとこのひと | man | |
| 劣る | おとる | to fall behind, to be inferior to | 2290 |
| お腹 | おなか | stomach | 710 |
| 鬼 | おに | ogre, demon | 2291 |
| 帯 | おび | band (e.g. conduction, valence) | 2077 1030 1189 |
| お昼 | おひる | lunch, noon | 2292 |
| オフィス | office | ||
| 溺れる | おぼれる | to be drowned, to indulge in (kids) | 2293 |
| お前 | おまえ | (fam) you (sing), presence (of a high personage) | |
| お目出度う | おめでとう | Congratulations!, an auspicious occasion! | |
| お目に掛かる | おめにかかる | to regard someone | |
| 思い出 | おもいで | memories, recollections, reminiscence | |
| 主に | おもに | mainly, primarily | |
| 思わず | おもわず | unintentional, spontaneous | |
| 親 | おや | parents | 647 648 697 |
| 親分 | おやぶん | chief, head | 647 |
| 泳ぎ | およぎ | swimming | 716 1614 |
| 凡そ | およそ | about, roughly, as a rule, approximately | 2294 fg139 |
| 及ぼす | およぼす | to exert, to cause, to exercise | 2295 yg62 |
| 居る | おる | to be (animate), to be, to exist | 1140 1195 |
| 下す | おろす | to lower, to let go down | 2296 |
| 降ろす | おろす | to take down, to launch, to drop | 2296 |
| 音 | おん | sound, note | |
| 音楽 | おんがく | music | |
| 恩 | おん | favor, obligation, debt of gratitude | 1210 |
| 恩典 | おんてん | favor, grace | 1210 |
| 温暖 | おんだん | warmth | 2297 |
| 温度 | おんど | temperature | 2297 |