worst 
(wûrst)
(wûrst)adj. Superlative of bad1, ill.
1. Most inferior, as in quality, condition, or effect: the worst hitter on the team.
2. Most severe or unfavorable: the worst winter in years.
3. Being furthest from an ideal or a standard; least desirable or satisfactory: This is the worst cafeteria!
adv. Superlative of badly, ill.
In the worst manner or degree.
tr.v. worst·ed, worst·ing, worsts
To gain the advantage over; defeat: was worsted in the argument.
n.
Idioms: Something that is worst.
at (the) worst
Under the most negative circumstances, estimation, or interpretation: At worst, the storm will make us postpone the trip.
get/have the worst of it
To suffer a defeat or disadvantage.
if (the) worst comes to (the) worst
If the very worst thing happens.
in the worst way Informal
Very much; a great deal: wanted to be elected in the worst way.
[Middle English, from Old English wyrsta; see wers- in the Appendix of Indo-European roots.]