mathematical function
nounUK /ˌmæθəˈmætɪkəl ˈfʌŋkʃən/
US /ˌmæθəˈmætɪkəl ˈfʌŋkʃən/
A mathematical function is a rule that takes a number in and gives exactly one number out.
The function f(x) = x + 2 adds two to every number you put in.
OTHER MEANINGS
2. A special purpose or activity of a person or thing.
The heart's main function is to pump blood.
3. A formal social event or ceremony.
They attended a charity function at the hotel.
4. To work or operate in a proper way.
The old clock still functions perfectly.