A faithful friend or devoted follower.
More example sentences
- ‘You see, but you do not observe,’ he tells his dull fidus Achates; how many steps, for example, are there from the hall to the room where they are sitting?
- This Isaac proved the most faithful of all his comrades, and stuck to him throughout the whole journey, a regular fidus Achates.
Definition of fidus Achates in:
- The British & World English dictionary