It's much worse than base vs. bass, and almost as tough as principle vs. principal. People have trouble with phase vs. faze. Even some journalists and copy editors get them mixed up. But except for the fact that the two words are pronounced in exactly the same way, they could hardly be more different.
A phase is a stage of development, a temporary pattern, a cyclically recurrent form, a stage in a periodic process, a form of matter, etc. Phase is basically a noun, though of course there is a denominal verb meaning to carry something out by phases, etc. According to the AHD, phase is a "back-formation from New Latin phasēs, phases of the moon, from Greek phaseis, pl. of phasis, appearance, from phainein, to show.
To faze someone is to disrupt their composure or disconcert them, from Middle English fesen "to drive away, frighten". There is no deverbal noun in common use.
But Google's News index currently has at least recent two "phase" errors from the NYT (both of which have expired from the paper's free archive):
Pace does not phase Sharapova, as she proved with her come from behind victory over the equally big-hitting American Lindsay Davenport in Thursday's semifinals.
These sorts of demands do not phase Ms. Kramen, who happily considers herself "a lifer."
And the BBC web site has a few more:
(link) But given that Later...is for a more refined audience, that's unlikely to phase him or his loyal supporters who'll continue to look forward to the next collection this time next year.
(link) Alone, his expletive tantrum did not phase the young dude at the wheel.
The internet at large is full of phase/faze confusions, in both directions:
It’s just a faze in the relationship, you’ll get over it sooner or later.
The present paper shows that introduction of an additional faze shift permits determination of very small displacements and also presents the portable interferometer and the technique for measurement of residual stress in field conditions.
It just got to the point where things like that didn't phase me anymore.
Kucinich not phased by Gephardt's early dropout
All the journalistic confusions that I've seen are in the direction of using phase in place of faze, rather than the other way around. If this is true, it's probably because phase seems like a higher-prestige word.
This is also true for the two examples of phase/faze confusion documented by the OED:
1889 'MARK TWAIN' Yankee at Crt. K. Arthur (Tauchn.) II. 154 His spirit -- why, it wasn't even phased.
1898 R. B. TOWNSHEND in Westm. Gaz. 19 Nov. 2/1 It don't seem to 'phase' him in the very slightest.
I first thought that only the accidents of 18th- and 19th-century spelling standardization prevented phase and faze from merging in the way that the Greek and Germanic variants of pole seem to have done. However, the OED's citations for phase start in 1812, and for faze in 1830. So neither word has been in use all that long, apparently, and they've probably been confused from the beginning, at least in one direction.
[NYT Sharapova citation from Maryellen MacDonald]
Posted by Mark Liberman at July 5, 2004 10:59 AM