kiddo
n. countable B2 Upper Intermediate UK //kˈɪdəʊ// kid·do
n. a friendly way to address a child or a younger person. You use it when you want to sound warm and casual.
n. an informal and affectionate form of address for a child or a younger person. Often used by adults to signal a protective or familiar relationship.
Don't worry about the mess, kiddo.
The coach patted the player on the shoulder and said you'll get them next time, kiddo.
While the term is meant to be endearing, using it with a younger colleague in a professional setting can sometimes come across as patronising rather than friendly.
From kid + -o; see kid (“child”).
Usage
Primarily used as a vocative (a word used to address someone directly).