Shortly after this conversation, Max and Lisa had another argument:
Max: Huh? What's going on?
Lisa: You're browsing the web with your smartphone instead of paying attention!
Max: I was sending a message to my sister!
Lisa: Oh, is she picking you up in her car after school?
Max: Yes, we're going to play music together.
Lisa: You should listen to the teacher, she's showing us the lower-case Greek alphabet.
Max: I care less about that than anything else!
What word did he miss this time?
This puzzle is inspired by the previous one, but it can be solved independently.