Meaning : Used as intensifiers.
Example :
Terribly interesting.
I'm awful sorry.
Synonyms : awful, frightfully, terribly
Meaning : Of a dreadful kind.
Example :
There was a dreadfully bloody accident on the road this morning.
Synonyms : dreadfully, horribly
Meaning : In a terrible manner.
Example :
She sings terribly.
Synonyms : abominably, abysmally, atrociously, rottenly, terribly