function expression
nounUK /ˈfʌŋkʃən ɪkˈspreʃən/
US /ˈfʌŋkʃən ɪkˈspreʃən/
A function expression is a way to write a piece of code that does a job and give it a name.
She used a function expression to add two numbers together.
OTHER MEANINGS
2. In mathematics, a function expression is a formula that shows how one value depends on another.
The function expression f(x) = x + 2 doubles the input.
3. A facial or bodily look that shows what someone is doing or feeling.
His expression showed he was confused by the puzzle.
4. A phrase or group of words used to say something.
"Piece of cake" is a common expression for something easy.