Sweet! I'm going to try to find more.
I bet there are more too. Words are always being compounded and shortened. Meanings shift. The words that get joined together are usually already related to each other in some way (that's why they get put together). Imagine this scenario (which I am completely making up): some flubs are gub, so
gub flub becomes a unit that means something different than what the words mean separately, as
blackbird or
black bear. People shorten
gub flub to just
gub.
Flub already referred to flubs, and now
gub flub and
gub do so too. This seems common enough to me, especially if
gub was added as an adjective or verb and isn't already being used as a noun (its only meaning as a noun would be to refer to a gub flub -- it wouldn't have to 'compete' with any other nouns
gub. This might be what happened in English with, for example,
black or
blacks, as used as a noun to refer to people with a certain range of skin colors, national origin, or whatever the classification was based on. I'm not sure if it was clipped from
black people or not though. I'm almost certain this is what happened with my example below,
sabretoothed tiger (actually, (ack! it keeps getting more complex!) see,
sabretoothed is an adjective that could have been formed in different ways, some of which don't include a step with the noun
sabretooth, which might not have been a word until AFTER
sabretoothed tiger was clipped to
sabretooth. THEN
sabretooth was compounded (or compounded again, in a way) with
tiger to form
sabretooth tiger. Or people could have dropped the
-ed for other reasons. Bah, I will have to look into this one -- the history of the word is probably attested, so it's a good chance to test predictions. Sweetness). You just need to get
flub to take on the more specific meaning, gub flub, without adding any morphemes (words or parts of words) to it; this can be accomplished by
flub being used in a narrower context or by its other meanings dying or becoming less common.
It could happen in other ways, of course. That's just one option.
Bathtub, for example, was probably
bathing tub (
bathing being formed from the verb
bathe). So it's not necessarily so straightforward either. And they don't have to be compounds either.
Telephone, from below, isn't a compound. They don't even need to be [word]-noun compounds, though that type is, AFAIK, the most common.
Taperecord was meant as a verb, yes? (I've never head
taperecord used as a noun.)
Ack, don't post interesting stuff! I'm supposed to be doing homework!
Oh,
saber is more common than
sabre, it seems (if anyone else is looking (yeah, right)).