Plethora to me (British English) seems to suggest not so much a specific quantity, but diversity in items. "There were a plethora of options." Myriad definitel

Plethora to me (British English) seems to suggest not so much a specific quantity, but diversity in items. "There were a plethora of options." Myriad definitely feels much, much greater than 'many' - indeed, the proper definition is exactly ten thousand. At that point though, you wouldn't want to be the person counting the items :)