I didn't like to mention it before (he being your brother and all) but the moment I set eyes on your brother, I said to myself, "Treacherous." -- What does treacherous mean?
Dangerous, terrible or someone who betrays others
"But what'll they do to him Mr. Beaver?" gasped Lucy. -- What does gasped mean?
To inhale suddenly
He kept slipping into deep drifts of snow, and skidding on frozen puddles and sliding down steep banks. -- What does skidding mean?
To slide sideways, often on a slippery surface.