Here's a breakdown:
* பச்சை (pacchai) means "green"
* பயிறு (payiru) means "pulse" or "legume"
So, பச்சைப் பயிறு (pacchai payiru) literally translates to "green pulse".
You might also hear it called பச்சை மொச்சை (pacchai mochchai), which is more specific and refers to green gram split and peeled.