It's car-MEL with the stress on the second syllable.
In the bible it means garden, orchard or forest, often as opposed to the desert. It can be some sort of food (Leviticus 23,14 …)
Carmel can be a proper name: There is Mount Carmel (this is where the Carmelites had their monestary, before they were expelled and finally came to Spain, where the name Carmel was changed to Carmen; the Carmelite Mountains were famous before, because it was here, where Elijah was said to have killed the priests ob Baal, 1. Kings 18) and an ancient city of that name west of the Dead Sea.
The ordinary word for "garden" in Hebrew is "gan" like in "Gan Eden".
Tha name Carmel is or was used for several things:
http://en.wikipedia.org/wiki/Carmel