1 to screen

2 to block (sth or sb)

3 to shield

4 (protective) shield

1 to cover up (a shortcoming)

2 to screen off

3 to hide

4 to conceal

1 to blab

2 to shoot one's mouth off

3 to commit a gaffe

1 to deceive

2 to hoodwink

1 to cover (up)

2 to block

3 to obstruct

4 to shade

1 one word says it all (idiom, from Analects); to cut a long story short

2 in a nutshell

1 to cover up the truth on all sides (idiom)

1 lit. clothes not covering the body (idiom)

2 fig. poverty-stricken

1 lit. hiding the sky and covering the earth (idiom); fig. earth-shattering

2 omnipresent

3 of universal importance

1 to be secretive; to try to cover up (idiom)