She looked at him seriously.

In a way that shows deep thought or concern.
He spoke seriously about the issue.
They need to take this matter seriously.
I am seriously considering your proposal.
seriously injured
seriously ill
seriously important
earnestly
sincerely
gravely
She is seriously thinking about moving.

In a way that is important or not joking.
He is seriously considering a new job.
They are seriously worried about the situation.
I seriously doubt that will happen.
seriously think
seriously consider
seriously doubt
earnestly
sincerely
gravely