unset

Unset variable

$ unset [VARIABLE]

$ unset -f [function_name]

$ unset [VAR1] [VAR2]

unset [-f] [-v] name ...

unset removes shell variables. It's a builtin.
Variable removal. Clear from environment.
Function removal. Delete definitions.
Shell scope. Current shell only.
Clean environment. Remove unwanted.

-f

Unset function.

Unset variable (default).

Name to unset.

Shell builtin. Cannot unset readonly. Current session only.

unset is a standard shell builtin command for removing variables and functions from the shell environment.

export(1), set(1), env(1)