Indefinite pronoun—primary and most frequent use of the word.
Definitions
An unspecified or unknown thing; used when the exact nature of the thing is not important or not known to the speaker. There's something moving in the bushes.
A vague feeling, intuition, or influence, often personified as a subject. Something tells me we're going to be late.
Informal intensifying adverb (e.g., “something fierce”).
Definitions
To some degree; rather; somewhat (chiefly informal). The milk smelled something sour.
Synonyms
a bit
a little
to some extent
to a degree
kind of
sort of