inexpressive

Lacking expression; blank.

Devoid of emotion or style; flat or dull.

Not expressive; wanting expression; not distinctly significant or representative: as, an inexpressive gesture or portrait.

Not to be expressed; inexpressible; ineffable.

Inexpressible.

Without expression or meaning; not expressive; dull; unintelligent.

Lacking expression or emotion.

not expressive