unintern

unintern is a built-in function in `C source code'.

(unintern NAME OBARRAY)

Delete the symbol named NAME, if any, from OBARRAY.
The value is t if a symbol was found and deleted, nil otherwise.
NAME may be a string or a symbol. If it is a symbol, that symbol
is deleted, if it belongs to OBARRAY--no other symbol is deleted.
OBARRAY, if nil, defaults to the value of the variable `obarray'.