Clear away. Remove.
Clear off! Away with you! Take away. Clear out. Empty out, make tidy. ( See below, Clear Out For Guam.) Clear up. Become fine after rain or cloudiness; to make manifest; to elucidate what was obscure. To clear an examination paper. To floor it, or answer every question set.
To clear the air. To remove the clouds, mists, and impurities. To clear the dishes. To empty them of their contents.
To clear the room. To remove from it every thing or person not required. To clear the table To remove what has been placed on it.
Clear the Court
Remove all strangers, or persons not officially concerned in the suit.
Clear the Decks
Prepare for action by removing everything not required. Clear used adverbially means wholly, entirely, as, “He is gone clear away,” “Clear out of sight.”
A clear head. —A mind that can understand clearly anything which it grasps. A clear statement. A straightforward and intelligible statement.
A clear style [of writing] A lucid method of expressing one's thoughts.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894