(not) anything; (nothing) at all; (not) any
Used with a negative verb to emphasize a complete lack or absence. Stronger than 何も alone; often translates as 'nothing at all' or 'not a single thing'.
See also: 何も
There is nothing at all in the fridge.
He knew absolutely nothing about that matter.
He doesn't know anything at all about the matter.
She was angry, but she didn't say anything at all.