1.Slang or short for electrode. Electrodes are small patches of electrically conductive material that can be attatched to the body to monitor vital signs or stimulate muscles.
2. 'trodes' are also the plug part on the end of an electrical cord.
3. Sexual connotation, a dick.
Chris said "dude, why isnt the stove working"? Paul replied, "Hey man, they trodes aren't plugged in!"
"dude, i totally plugged my trode into that bitch."