What is the meaning of Fido?

A coin that is defective, having been incorrectly minted, often prized by collectors.

faith, trust

faithful, loyal

a credit concession

first-person singular present indicative of fidare

to trust, put confidence in

to rely upon

dative/ablative masculine/neuter singular of fīdus (“trustworthy; faithful”)

faithful, loyal

Source: wiktionary.org