faatupu, faa-tupu faatupui, faa-tupui

faatupua,  v.n. to be silent, grave, serious.
— a. reserved; also sullen.
— s. reservedness, sullenness. [Dav : 2179]
faa-tupua,  a. pn. Ítre morne, silencieux. [Jau :899] (note)