Lion is an apex predator. Such a trophic level assigned to it indicates that

Apex predators have powerful effects on other predators, on herbivores, and on plants, they can be important in nature conservation. Many of the predators are keystone species maintaining diversity and stability in an ecosystem.

Biomass decreases lower to higher trophic levels.

Apex predators are carnivores.

Top carnivores do not have many predators.