Select the most appropriate one-word substitution for the given group of words.

A sly look that is evil or with bad intent 

Leer 

The most appropriate one-word substitution for "a sly look that is evil or with bad intent" is leer.

• Peek means to look quickly and furtively.
• Meek means timid or submissive.
• Sleek means smooth and shiny.

The word leer comes from the Old English word "leorian," meaning "to look askance." A leer is a long, steady, and often suggestive look. It is often used to express lust, greed, or malice.