i used the word infirm recently, --and thought about it..

its clear how we get the word..
(from the American heritage dictionary, vie one look)
ETYMOLOGY: Middle English infirme, from Old French, from Latin infirmus : in-, not; see in–1 + firmus, strong, firm

but while firmus clearly is related to FIRM and firm can mean strong, we never (well i can't think of any examples) call healthy
people firm.. they might be strong, (as an ox) or hearty, or well, or lots of other words.. but firm?
infirm is another word like uncoth.. Infirm is not well, but Firm is not a common word for in good health or well
--
and since we have had several discussion of words like uncoth, etc. i put it here. i didn't think it was imporant enought to be discussed to death..


my other obsession