Definition of "Familiar" :

noun: a spirit (usually in animal form) that acts as an assistant to a witch or wizard

noun: a friend who is frequently in the company of another

noun: a person attached to the household of a high official (as a pope or bishop) who renders service in return for support

adjective: having mutual interests or affections; of established friendship

"On familiar terms."

adjective: well known or easily recognized

"A familiar figure."

adjective: within normal everyday experience; common and ordinary; not strange

"Familiar ordinary objects found in every home."

adjective: (usually followed by with') well informed about or knowing thoroughly

"Familiar with the complex machinery."