Introduction:
The animal that has a pair of visible, big teeth not meant for eating is the Elephant. Elephants have tusks, which are elongated, modified incisor teeth that grow out of the upper jaw.

Tusks:
- Elephants have two tusks, one on each side of their face. These tusks can grow up to several feet in length and can weigh hundreds of pounds.
- Tusks are visible and prominent, protruding outwards from the elephant's mouth.
- They are composed of dentin, a hard substance similar to that found in human teeth.
- Tusks continue to grow throughout an elephant's life, and their growth rate varies between individuals.

Functions of Elephant Tusks:
- Defense: One of the main functions of tusks is defense. Elephants can use their tusks to protect themselves from predators by charging or jabbing with them.
- Mating Displays: Male elephants often use their tusks during mating displays. They may engage in tusk-to-tusk combat to establish dominance and win the attention of females.
- Foraging: Although tusks are not meant for eating, elephants can use them to dig for food or water. They can strip bark from trees or dig into the ground to access roots or water sources.
- Communication: Elephants also use their tusks for communication. They may touch tusks with other elephants as a form of greeting or to establish social bonds.
- Symbol of Age and Dominance: The size and shape of an elephant's tusks can indicate its age and social status within the herd. Older and dominant males tend to have larger tusks.

Conclusion:
In conclusion, elephants have a pair of visible, big teeth known as tusks. These tusks are not meant for eating but serve various functions such as defense, mating displays, foraging, communication, and as a symbol of age and dominance.