Definition of "HMS"

(military, nautical) Initialism of His/Her Majesty's Ship (prefix for ships in the navy of a monarchy, such as the British Royal Navy).

(postage) Initialism of His/Her Majesty's Service.  examples

(mathematics) Initialism of hour-minute-second.:

1. A format for writing decimal angles.  examples

2. A 24 or 12-hour time format that includes seconds, in addition to hours and minutes.  examples

3. A format for writing decimal time, usually associated with base-10 time such as during the French Revolution.  examples