similes and idioms

Good afternoon,

I wanted to know wath that simile meens:
- "I'd be avoiding that place like tha plague"

And what those idioms meen:
- "...bagged the deer"
- "That splendid young man cut down in his prime"

[Anglika]

I avoid that place like the plague - Plague is a nasty disease, so I will avoid it if I can.

What is the context for "bagged the deer"? The obvious one is that you have shot the deer.

That splendid young man cut down in his prime - He died when still a young man in the prime of life, the time of maturity when power and vigour are greatest