口先のうまい

くちさきのうまい

smooth talking

口がうまい

くちがうまい

honeymouthed, glib, fair-spoken, cajoling, talking glibly

口の堅い

くちのかたい

tight-lipped, able to keep a secret

口の軽い

くちのかるい

loose-tongued, talkative

口の悪い

くちのわるい

sarcastic, foulmouthed, having a sharp tongue, having a sharp nasty tongue

口舌の争い

こうぜつのあらそい

war of words, quarrel, dispute

口数の多い

くちかずのおおい

talkative

口の小さい

くちのちいさい

small mouthed

宵の口

よいのくち

nightfall, early evening

口の端

くちのは

gossip

人の口

ひとのくち

what people say, rumours, public opinion

序の口

じょのくち

lowest division

竜の口

たつのくち りゅうのくち

dragon-head gargoyle, gutter spout

道の口

みちのくち

the part of a province closest to the capital

がま口

(coin) purse with a metal clasp

どの口が言う

どのくちがいう

I don't want to hear it from you, are you in any position to say that?

口のきけない

unable to speak; inarticulate

口数の少ない

くちかずのすくない

taciturn

口は災いの門

くちはわざわいのかど

words can lead to disaster; the tongue is the root of calamities; the more you open your mouth the more likely you are to put your foot in it