I know that
$$\lim_{x \to \infty} f(x)=L \mbox{ means } \forall \varepsilon>0 \:\exists N\:\forall x\:(x>N\rightarrow|f(x)-L|<\varepsilon)$$
$$\lim_{x \to a} f(x)=\infty \mbox{ means } \forall N \:\exists \delta>0\:\forall x(0<|x-a|<\delta|\rightarrow f(x)>N)$$
I've combined these the following way but not sure if it's precise:
$$\lim_{x \to \infty} f(x)=\infty \mbox{ means } \forall M \:\exists N\:\forall x\:(x>N\rightarrow f(x)>M)$$
Is it correct definition of this limit?
Definition:
For all $\epsilon \in \mathbb R_+$ exists $k$, such that for all $x$
$$|f(x)|>\epsilon,\space \space \text{when} \space x>k.$$
So yes it appears correct.