Fang and Fangs

Fang noun - Canine tooth of a carnivorous animal; used to seize and tear its prey.

Fangs and fang are semantically related in dentition topic. In some cases you can use "Fangs" instead a noun "Fang", when it comes to topics like plural of tooth.

Fang and fangs are semantically related in small appendage of animate being topic. You can use "Fang" instead a noun "Fangs", if it concerns topics such as bony object in mouth, hard bony structure in the jaws of vertebrates, nail of animal, main part of device.