No, a kern is the funny little piece that sticks out and hairline is the thin part of a character.

Technically the f probably contains the only kern -- but the way I'm using the term here is really only relevant to metal. We don't usually use kern to refer to a part of the letterform that projects beyond the sidebearings anymore, now that the type body is no longer physical.

(And I doubt that those parts of the a and g project beyond the sidebearings; but I'd have to crack open Minion and take a peek.)

That is to say, "kern," as a noun, is no longer used to describe an attribute of a glyph shape, but rather a relationship in the glyphs metrics, and only makes sense in the context of a specific pair of glyphs.

The indicated portion of the a is probably most often called simply a "terminal." That part of a g is usually called the "ear."

-- K.

We've nattered over the meaning of terms here before but Kent's description of kern/kerning is widely accepted. In regards to your definition of hairline. My understanding is that it is not merely the thin stroke of a letter but the thinnest possible stroke of a letterform. In other words, your Bodoni sample contains hairline strokes and serifs, your Minion sample does not.

Well, it appears that I'm among experts after all. That's what I wanted to find out. Good to know. Thanks for the criticism.

Kentlew, thx for the clarification. These terms originated from my days designing typefaces at Mergenthaler in the 80's when type was making the transition from metal to film.
Ken the hairline definition came from Ed Benguiat's typography class where he used the term the way we did at Merg as well – to delineate the thick and thin parts of a character.
Paul, thx for the clarification – I agree I should have used a thicker serif.
Stephen, thx for pointing me to Fontshop's anatomy. I found it useful
Eluard, many students in lectures have found this diagram useful, even if it may not be 100% according to everyone's definition here. i will amend it – but I wont repost it.
Thx to all.