Frantic, Desperate, Certain Death, Sure Death
な adjective, の adjective
Your future consists of certain death. How would you feel in this situation? Probably very frantic and desperate. Another translation for this word is simply certain death, though I'd rather you learn one of the first two before this one if you can.
ひっし
The readings are the on'yomi readings, though 必 (ひつ) gets shortened to ひっ. In your desperate situation just imagine that you're trying to get out of it, and to do so you move the つ only to find a smaller っ blocking your way. It is certain death.
お母さんは、ダイエットに必死だ。
Mom is frantic about losing weight.
必死に走ったが、バスはもう出てしまった。
I ran desperately, but the bus had already left.
必死のプロポーズだったが、ダメだった。
It was a desperate proposal, but it wasn't successful.