Citrus peel used as a garnish in cocktails, say

Round-bottomed fruit4 ___ capita income (income for each person)3 Incoming flight information: Abbr.3 ___ Arbor, Michigan3 "It's all the ___ these days" (popular trend)4 Conk on the head3 Sheldon Cooper's catchphrase on "The Big Bang Theory"7 Cry heard at a soccer stadium3