Blowdry

John Lawler has an undated (1995) posting on odd English forms in which he says:

I mentioned "wake in the present perfect" because it's my best example of an English "defective" verb; i.e, one that lacks a principal part, in this case the past participle, the one that's used in the present perfect construction. ... Other English defective verbs include 'beware' (usable in the imperative only), 'blowdry' (try forming the past tense and you'll see what I mean), 'born' (technically, a "deponent" verb, with only passive forms), and the modal auxiliaries, but they're so irregular anyway that's hardly surprising. Latin had lots more.

I've always said "have waked", myself, but I'm not going to argue it with him. But the first time I read that I said: "Huh? Blowdried, dude." Today's Zits bears that out - the joke isn't about how to conjugate blowdry, but how to define it.