Now I know I'm still half asleep and shouldn't be answering questions yet!!! Thanks klazomaniac - I think I 'saw' the answer but made a dog's dinner of it.
some thing; a certain undetermined or unspecified thing:
Something is wrong there. Something's happening.
an additional amount, as of cents or minutes, that is unknown, unspecified, or forgotten:
He charged me ten something for the hat. Our train gets in at two something
Ah those folk who remember word type definitions and can identify them. For some reason my memory never could recall them. Better with numbers than words.
My "I thought it was an adverb" referred to the suggestion of PERHAPS as the pronoun . I initially overlooked the something as I wrongly took the "say something''as the definition