argumate

I suddenly realised I have no idea how to refer to the round objects used in a game of baseball

baseballs? doesn’t sound right

baseball balls? surely not

mitigatedchaos

That’s what they are, Argumate.  One is a baseball, more are baseballs.

“About the size of a baseball.” “He hit a baseball over the fence.”  Etc.

I feel like maybe you don’t belong in America (or Japan).

(Nah I’m just kidding, Japanese would probably use some counter so the plural form wouldn’t be “baseballs” (per se).)