| 口 | くち | mouth; opening; hole; gap | n5 |
| 入口 | いりぐち | entrance; entry; gate; approach | n4 |
| 口惜しい | くやしい | frustrated (over a failure, humiliation or injustice); annoyed; chagrined; (bitterly) disappointed | n3 |
| 人口 | じんこう | population; common talk | n4 |
| 口調 | くちょう | tone (of voice); manner of talking | |
| 悪口 | わるぐち | (verbal) abuse; speaking ill of people; bad-mouthing; name-calling | n2 |
| 惡口 | わるぐち | (verbal) abuse; speaking ill of people; bad-mouthing; name-calling | |
| 戸口 | とぐち | door; doorway | |
| 裏口 | うらぐち | backdoor; rear entrance; rear exit; unauthorized | n1 |
| 出口 | でぐち | exit; way out; outlet; vent | n5 |
| 口実 | こうじつ | excuse; pretext | n1 |
| 閉口 | へいこう | to be stumped; to be at a loss; to be at one's wits' end; to be nonplussed | n1 |
| 門口 | かどぐち | door; entrance; gateway | |
| 口々 | くちぐち | every person; every mouth; every entrance | |
| 利口 | りこう | clever; intelligent; bright; smart | n2 |
| 一口 | ひとくち | mouthful; morsel; bite; gulp | n2 |
| 口笛 | くちぶえ | whistle (sound made with the lips) | n1 |
| 窓口 | まどぐち | counter; window; teller window; ticket window | n3 |
| 口コミ | くちコミ | word of mouth; comments written online (about a product, service, etc.); online reviews | n1 |
| 無口 | むくち | taciturn; reticent; quiet; silent | n2 |
| 口上 | こうじょう | vocal message; speech; statement; prologue at the start of a kabuki performance | n4 |
| 山口 | やまぐち | Yamaguchi (city, prefecture) | |
| 口説く | くどく | to persuade; to urge; to coax; to solicit | |
| 口癖 | くちぐせ | pet saying; favorite phrase; stock phrase; catchphrase | n1 |
| 早口 | はやくち | fast-talking; rapid talking | n2 |
| 口元 | くちもと | mouth; lips; shape of the mouth; near an entrance | |
| 口走る | くちばしる | to blurt out; to let slip; to say inadvertently; to come out with (e.g. nonsense) | |
| 袖口 | そでぐち | cuff; armhole | |
| 口吻 | こうふん | way of speaking; intimation; lips; mouth | n2 |
| 勝手口 | かってぐち | kitchen door; back door; service door; tradesman's entrance | |
| 傷口 | きずぐち | (opening of a) wound; cut | |
| 入り口 | いりぐち | entrance; entry; gate; approach | n4 |
| 口座 | こうざ | account (e.g. bank) | n2 |
| 口ぶり | くちぶり | way of speaking; intimation | |
| 川口 | かこう | mouth of river; estuary | n1 |
| 大口 | おおぐち | big mouth; mouth opened wide; boastful speech; tall talk | n1 |
| 口論 | こうろん | quarrel; argument; row; (verbal) dispute | |
| 口数 | くちかず | number of words a person speaks; number of dependents; number of mouths to feed; number of shares, items, applications, etc. | n1 |
| 口先 | くちさき | lip service; mere words; professions; lips | |
| 出入口 | でいりぐち | exit and entrance | n3 |
| 口ずさむ | くちずさむ | to hum (a tune); to sing to oneself; to croon | |
| 河口 | かこう | mouth of river; estuary | n1 |
| 口もと | くちもと | mouth; lips; shape of the mouth; near an entrance | |
| 口ごもる | くちごもる | to hesitate to say; to mumble; to hem and haw; to falter | |
| 口髭 | くちひげ | moustache; mustache | |
| 猪口 | ちょこ | sake cup; small deep porcelain bowl for serving food | |
| 間口 | まぐち | frontage; width (of a building, plot of land, etc.); breadth (e.g. of one's knowledge); scope (e.g. of one's work) | |
| 宵の口 | よいのくち | nightfall; early evening | |
| 口真似 | くちまね | mimicking someone's speech; imitating someone's way of speaking; mimicry | |
| 口外 | こうがい | revealing (information, a secret, etc.); disclosure; telling; letting out | n3 |
| 口中 | こうちゅう | interior of the mouth; oral cavity | n1 |
| 口紅 | くちべに | lipstick | |
| やり口 | やりくち | way (of doing); manner; method | |
| 表口 | おもてぐち | front door | |
| 口早 | くちばや | fast (talking); rapid; quick-tongued | |
| 手口 | てぐち | modus operandi; criminal technique; trick | |
| 切り口 | きりくち | cut end; section; opening; slit | n1 |
| 山口県 | やまぐちけん | Yamaguchi Prefecture (Chūgoku area) | |
| 山口縣 | やまぐちけん | Yamaguchi Prefecture (Chūgoku area) | |
| 口頭 | こうとう | oral; verbal; spoken; parol | n1 |
| 異口同音 | いくどうおん | (saying) with one voice; unanimously; in chorus; in unison | |
| 口止め | くちどめ | forbidding mentioning (something to others); imposing silence (on); ordering (someone) to keep quiet; muzzling (someone) | |
| 口火 | くちび | fuse; pilot light; cause (of a war, argument, revolt, etc.); origin | |
| 切口 | きりくち | cut end; section; opening; slit | n1 |
| 水口 | みずぐち | spout | |
| 口絵 | くちえ | illustration appearing in the first pages of a publication; frontispiece | |
| 火口 | ひぐち | burner; nozzle; origin of a fire | |
| 糸口 | いとぐち | beginning; start; first step; clue | n2 |
| 絲口 | いとぐち | beginning; start; first step; clue | n2 |
| 銃口 | じゅうこう | gun point; muzzle | n1 |
| 口辺 | こうへん | around one's lips | |
| 口やかましい | くちやかましい | nagging; critical; talkative; gossipy | n1 |
| 口碑 | こうひ | oral tradition; legend; folklore | |
| 告げ口 | つげぐち | telling (on someone); tattling; snitching | |
| 噴火口 | ふんかこう | (volcanic) crater | |
| 庭口 | にわぐち | garden entrance | |
| 口許 | くちもと | mouth; lips; shape of the mouth; near an entrance | |
| 無駄口 | むだぐち | chatter; idle talk | |
| 口出し | くちだし | meddling (in); butting in; interference; poking one's nose into | n1 |
| 口説 | くぜつ | lovers' tiff; quarrel between lovers; chattering; idle talk | |
| 鯉口 | こいぐち | opening of a scabbard; mouth of a sword sheath; style of shirt with carp-mouth shaped sleeves | |
| 陰口 | かげぐち | malicious gossip; backbiting; speaking ill behind someone's back | |
| 口説き | くどき | entreaty; imploring; begging; spoken portion of a song | |
| 口腔 | こうこう | oral cavity; mouth | n5 |
| 口語 | こうご | spoken language; colloquial speech; (modern) spoken Japanese; written style based on (modern) spoken Japanese | n1 |
| 小口 | こぐち | cut end; edge (of a page, etc.); small amount; small quantity | |
| 木口 | きぐち | grade of wood; quality of wood; end grain; cut end | |
| 口振り | くちぶり | way of speaking; intimation | |
| 軽口 | かるくち | talkative; loose-lipped; persiflage; frivolous talk | |
| 口添え | くちぞえ | recommendation; putting in a good word for someone | |
| 口ぐせ | くちぐせ | pet saying; favorite phrase; stock phrase; catchphrase | n1 |
| 口述 | こうじゅつ | dictation; verbal statement | |
| 口つき | くちつき | (in the shape of a) mouth; mouthpiece (of a cigarette); manner of speech | |
| 吸口 | すいくち | mouthpiece; cigarette holder; cigarette filter (tip); fragrant garnish (for soup) | |
| 口汚い | くちぎたない | foul-mouthed; foul (language); abusive; greedy | |
| 口伝 | くでん | oral instruction; passing information by word-of-mouth; oral tradition | |
| 出入り口 | でいりぐち | exit and entrance | n3 |
| 口径 | こうけい | aperture; bore; calibre; caliber | n2 |
| 口唇 | こうしん | lips | n2 |
| 糊口 | ここう | bare livelihood; subsistence | n1 |