Deer always have two antlers. It is the number of points on the antler that indicate the age.
By there fur
Any age.
Deer and pigs
twice the age of your mother
The vast majority of people, by far, never kill a deer.
Male deer are called bucks. At any age. The word sought here may be stag, which is a mature male deer. Five seems like an arbitrary cut-off, though.
The age of a deer is determined by their teeth, which unfortunately, you're not going to get a look at unless it's dead.
a few weeks after birth
In the wild, deer may live ten years. However in captivity with no predators or automobiles to worry about, deer may live to age 20.
about a year faster
A deer does not turn into a moose. It always stays a deer. The two are different animals.