Found on David Crystal's blog, DCBlog:

For the man who complains about people using words in senses which the dictionary has yet to record:

HAIL TO THEE, O ENGLISH USAGE PURIST
by Kate Gladstone

(tune: "The Irish Rover")

People say the English tongue
Is coming quite unsprung,
When words get new meanings, lose the ones they had.
Check the Oxford Dictionary,
And you'll find this isn't scary,
Degenerate, or new, or even bad.

In the days of Chaucer, once
You called your friend a DUNCE,
And meant he was a high-class intellectual:
But if you called somebody NICE,
What you meant, to be precise,
Was to label him as dim and ineffectual.

CHORUS: They lament what we've done
To the old mother tongue,
Howling "crime" and claiming multitudes misuse it ...
If they'd practice what they preach,
They'd speak eight-hundred-year-old speech ...
If they won't, they shouldn't say that we abuse it.

If you call word-changes bad,
And you say they make you SAD --
This, eight hundred years ago, meant down-to-earth ...
If all usage must be old,
Then STARVE is "die of cold,"
And AMUSED is "stunned," instead of "touched by mirth".

NAUGHTY now means nothing much --
An infant's prank or such --
But long ago in Chaucer's day medieval,
Or even Shakespeare's time,
It meant "hostile", "prone to crime",
"Worthless" (morally, or otherwise), and "evil."

CHORUS:

If you call a girl a HUSSY,
And she gets all mean and fussy,
Say you haven't cast aspersions on her life,
Tell her that your speech is pure,
And she therefore should be sure
That you meant -- like men of old -- she's a "housewife."

Find an English-usage smarty
And invite him to a party.
Offer POISON. He will think you've lost your mind.
You should whine and act offended
That your friendship now is ended,
Like the former meaning: "drink of any kind."

CHORUS:

He'll call your behavior AWFUL.
As a compliment it's lawful
To accept this, for as such it has no flaw --
If words mustn't ever change
To new meanings, it's not strange
That he kindly found his host "inspiring awe."

If they call me SILLY, I'll
Just bow my head and smile --
For this once meant "holy," also "full of joy" --
So this word you surely may
Use of anyone today
Whose devotion to old meanings might annoy.

CHORUS:

[L'envoi:]
I hope you liked this song,
And you didn't find it long --
Call it PRETTY and I'll know just how you feel:
If changed meanings are obscene,
"Crafty's" all that word may mean,
And the meaning of "attractive" can't be real!