brush up
Improve a skill quickly
brush off
Ignore, pay little attention
brush aside
To disregard, dismiss or ignore something, as unimportant.
To defeat with ease.
brush down
Used other than as an idiom: see brush,‎ down. To remove something with a brush, or ones hands using a downward brushing motion.
To straighten up one's clothes and to tidy up one's appearance.
brush by
To walk past another person, touching them slightly, normally by accident, and ignoring them.