razz
To tease someone in a playful, friendly way.
To razz someone means to tease them playfully, usually about something silly or embarrassing they did. When your teammates razz you for striking out in kickball, they're not being mean: they're joking around in a friendly way. You might razz your brother for wearing mismatched socks, or your friends might razz you for tripping over your own shoelaces.
The word carries a lighthearted feeling. Good-natured razzing happens between people who like each other and can laugh together. It's different from bullying or cruel mockery. When you razz someone, there's no real sting to it: you're just having fun at their expense for a moment, and they'll probably razz you right back when you mess something up.
You might hear razzing used as a noun, too: “I took a lot of razzing for forgetting my lines in the school play.” When you razz someone, it's like making a silly, rude noise with your words instead of with your mouth.