Yes, "etwas" may mean "somewhat/a little", e.g. "Es war etwas kalt im Schloss" = It was somewhat/a little cold in the castle" (et)was and irgend(et)was (the "et" may be left out, especially in spoken German) are sometimes used interchangeably. However, you'd always use "irgend(et)was" when you mean "something/anything at all, no matter what; something, but not anything in particular", e.g. Möchtest Du etwas/irgendetwas essen? (Would you like something to eat?) - Ja, bitte. (Yes, please.) - Was denn? Obst? Kuchen? Nudeln? (Well, what? Fruit? Cake? Pasta?) - Ach, irgendwas. (Anything (will do)) Sag bitte (et)was. Irgend(et)was. (Say something, please. Anything.) Er hat überhaupt nicht mit mir gesprochen! (He didn't talk to me at all!) - Na, irgendwas muß er doch gesagt haben. (Well, he must have said SOMEthing.) - Ja, als ich gegangen bin, hat er (irgend)was gemurmelt, was ich nicht verstanden habe. (Yes, as I was leaving, he mumbled something I didn't understand.)