Definition of "Worst" :
noun: the weakest effort or poorest achievement one is capable of
"It was the worst he had ever done on a test."
noun: the greatest damage or wickedness of which one is capable
"The invaders did their worst."
noun: the least favorable outcome
"The worst that could happen."
verb: defeat thoroughly
adjective: (superlative of bad') most wanting in quality or value or condition
"The worst player on the team."
adverb: to the highest degree of inferiority or badness
"She suffered worst of all."