adjective

1. in a decayed or decomposed state; spoiled, putrefied, tainted, etc.
2. having a bad odor because of decomposition or decay; putrid; foul-smelling
3. morally corrupt or offensive; dishonest, open to bribery, etc.
4. unsound or weak, as if decayed within
5. soft or easily broken as because of decomposition; friable: said of rocks, ice, etc.
6. Slang very bad, unsatisfactory, nasty, etc.

Etymology: ME roten < ON rotinn < IE *reud- < base *reu-, to tear, rip open (> rude): prob. used orig. of flax left to soak and rot