boo–boo 
/ˈbu:ˌbu:/ noun
plural boo–boos /ˈbu:ˌbu:/ noun [count] informal 1 : a small injury (such as a bruise or scratch) — used especially by children or when speaking to children ▪ She fell down and got a boo-boo. ▪ Did you get a boo-boo? 2 : a foolish or careless mistake
▪ I made a slight boo-boo when I added up the numbers. ▪ a major diplomatic boo-boo
▪ I made a slight boo-boo when I added up the numbers. ▪ a major diplomatic boo-boo
