He was excessively fat and had a sinister and aggressive expression.

A deep frown appeared between her brows, giving an almost sinister expression to her face.

A very sinister expression came over the face of the prostrate one, and he slowly clambered to his feet.

His eyes were big and dark, frank-looking, yet now and again with sinister expression in the corners of them.

The familiar sound of one of those voices caused a sinister expression to cross his dark face.

There was something in the tone of this reply, which made Uriah look at the speaker again, with a very sinister and suspicious expression.

A somewhat sinister expression, that, don't you think?

A sinister expression played upon the gray-haired man's lips.

It was obvious by the man's sinister expression that he intended to strike back at her hard.

Perhaps something can be made of this, he smiled - and a Klingon's smile is a sinister expression.