Definitions:

1. to darken completely verb
   • I blacked out the private information before releasing the documents to the public.
2. to lose consciousness due to a sudden trauma verb
   • I blacked out when I heard my friend passed away.
3. to obliterate or extinguish verb
   • We blacked out the parts we don't like.
4. to suppress by censorship as for political reasons verb
   • I blacked out the documents before filing.

Synonyms:

• blacken out
• zonk out