A "heteronym" is a word that has two different pronunciations and a different meaning for each pronunciation:
Examples:
CONflict (noun, a fight) - conFLICT (verb, to disagree)
CONtent (noun, information - conTENT (adjective, happy)
CONverse (noun, the opposite) - conVERSE (verb, to speak)
DESert (noun, hot & dry land) - deSERT (verb, to leave without permission)
MINute (noun, 60 seconds) - miNUTE (adjective, very small)
OBject (noun, a thing) - obJECT
PERmit (noun, paper that gives permission) - perMIT (verb, to allow)
Notice that when the stress is placed on the first syllable, the word is normally a noun. When the stress is placed on the second syllable, the word is normally a verb or an adjective.
If you would like to see more, you can find a longer list here: http://www-personal.umich.edu/~cellis/heteronym.html
