so ill or so badly injured that you might die [↪ fatally]:
10 people died and 30 were critically injured in a rail crash yesterday.
She is still critically ill in hospital.
in a way that is very important [= crucially]:
The success of the project depends critically on the continuation of this funding.
This is a critically important meeting.
in a way that is very serious and worrying [= dangerously]:
Food supplies are at a critically low level.
in a way that shows you are criticizing someone or something:
Mike looked at her critically.
He has spoken critically of the government's refusal to support the industry.
thinking about something and giving a careful judgment about how good or bad it is:
We teach students to think critically about the texts they are reading.
according to critics who give judgments about art, films, theatre, and books:
The play was critically acclaimed (=praised by critics) when it opened in London last month.