A question (confusion) about closure

Hi,

I have a confusion regarding closure and its definition. As per Paul
Graham:

When a function refers to a variable defined outside it, it=92s called a
free variable. A function that refers to free lexical variable is
called a closure.

However as per CLHS a closure or lexical closure is:

lexical closure n. a function that, when invoked on arguments,
executes the body of a lambda
expression in the lexical environment that was captured at the time of
the creation of the lexical closure, augmented by bindings of the
function's parameters to the corresponding arguments.

lexical environment n. that part of the environment that contains
bindings whose names have lexical scope. A lexical environment
contains, among other things: ordinary bindings of variable names to
values, lexically established bindings of function names to functions,
macros, symbol macros, blocks, tags, and local declarations (see
declare).

Can any pro lisper kindly help me?

Thanks,
Samik
Blog: http://lispsamik.blogspot.com/