last word in text

Is there a function or composition of functions that will retrieve the last
word in a text field? I have a table of addresses with arbitrary text
for the first field (i.e. to whom it is addressed), and I'd like to do my
queries as something like this:

SELECT * from Addresses
WHERE state = 'CA'
ORDER BY lastword(addressee);

What I'm missing is the definition/name of the lastword function.

Note that I'm not expecting perfect results from this. There will be some
weirdness with certain addressees. Nonetheless, it is a reasonable
approach. My other option, which is what I'm doing now, is to have a "last"
column in the table and have my host language fill it on insertion. It's
workable, but it's redundant and overly complex from a data abstraction
point of view.

--Greg