transitive. To conceal, hide; to be silent about, disguise (a fact). Also absol. not to (or at) lain: not to be concealed.

with (an) open face: with an uncovered face, esp. one suggesting candour, sincerity, or simplicity of character (cf. openness, n. 2a); (hence)…

to (one's) teeth, to the teeth of: intensive of ‘to one's face’; directly and openly; defiantly; also, so as directly to face, confront, or oppose.

to wash one's dirty linen at home, in public: said figuratively with reference to domestic quarrels or grievances, the discussion of which is best…