AM and PM are associated with 12-hour timekeeping, as opposed to the international 24-hour clock. The 12-hour system grew up mainly in Northern Europe, and spread globally from there via the British Empire.
The adjective STRENUOUS has 2 senses: 1. characterized by or performed with much energy or force. 2. taxing to the utmost; testing powers of endurance. Familiarity information: STRENUOUS used as an adjective is rare.
THE INFO: Stamina can mean the difference between a workout that lasts for an hour and one that lasts for 10 minutes â or even whether or not you can get up the stairs without losing your breath. It's also what will help you achieve further fitness goals.