1. a soft or confidential tone of voice; a whispered word or phrase.
'she spoke in a whisper'
'I'll miss you.' He mutters quietly to the metamorphmagus girl he fell for so long ago. 'It's not like I'm leaving, Remus. I'll be back in an hour.' She whispers humorously.
'But it already feels like you've been gone for so long.'
'Look.. Just whisper to the map, and it'll tell you where I am. I charmed it to be that way.'