This then is contrasted with the intension of a term.

It should be noted that extensions may come to vary: Once there were many Mohicans; then there was the last of the Mohicans; and then there were no Mohicans at all.

Also, some extensions of some terms may be infinite ('natural number', 'real number'), and if Cantor is right there are - in some sense - infinities of infinitely many sizes. (See: Set theory)

Another noteworthy point is that the extension of a predicate or relation (such as 'is green' or 'loves') is not quite the same sort of thing as the extension of a name, at least intuitively.

And variables have no extension, but their constant substituends do.