yes feverishly is an adverb. It tells how ex: He wrote feverishly to complete is work on time. feverishly describes how he wrote.
She searched feverishly through her notes for the elusive answer.
I feverishly layed in bed.
The crew is working feverishly to finish our project on time. She's only spoken feverishly, today.
She worked feverishly to meet the deadline, typing away without a break.
Two main uses I can think of: "Sick and frail, the old man moaned feverishly as he covered himself with a blanket." "The crazy spinster feverishly warned of impending Armageddon to passers by."
calmly
Depending on the usage, the opposite of the adverb feverishly could be calmly, or deliberately, or slothfully. Others could be coolly, serenely, or unexcitedly.
synonym
Apparently nowhere....I too have been searching feverishly for the same info.....
Big on the Web - 2010 White House Trends Feverishly Online as House Works on 4th 2-92 was released on: USA: 5 July 2011
you go down the street and start feverishly blowing as many men as you can.