Does the term 'silver nitrate' express all of its constituent chemical elements?
You should know that nitrate is a polyatomic ion with the molecular formula $\ce{NO3^-}$. For example:

Sulfate is a polyatomic ion with the molecular formula $\ce{SO4^{2-}}$;
Sulfite is a polyatomic ion with the molecular formula $\ce{SO3^{2-}}$;

Nitrate is a polyatomic ion with the molecular formula $\ce{NO3^-}$;
 Nitrite is a polyatomic ion with the molecular formula $\ce{NO2^{-}}$

At first glance, the nomenclature of the polyatomic negative ions seems difficult. 
When the name of the ion  ends in either -ite or -ate:


The -ite ending indicates a low oxidation state.
The -ate ending indicates a high oxidation state.


I agree with you that at the beginning, it seems difficult. But by practicing, you find this quite easy.