禪
禪 – Chan2 – Buddhism, Meditation, Chant
口頭禪 – Kou3 Tou2 Chan2 – Mouth Head Mantra
A 口頭禪 is a word of phrase that a person seems to use all the time. One of mine might be “somehow”. By the way, 口頭 kind of means the same thing as “tip of your tongue”.
I was almost thinking that “chant” might be related somehow to “禪” but of course I was wrong.