I want to hide "Milestone" header from Milestone time tracker .Is there a way to do it . 
2 Answers
Alternative way to do this we can create 1 custom empty LWC component where we can override the css of this window where we can hide the header.
Unfortunately, the answer is 'No' you cannot hide/remove milestone header as this is salesforce standard functionality. However if you still need this you might need to build custom component and add it in lightning console.
Thanks