What does it mean to "Exhaust" a card?

To "Exhaust" a card means to tap it until your next Awaken step in the context of the game. Tapping a card signifies that it is being used or activated for that turn, and it cannot be used again until it is readied or untapped, which typically happens during specific phases in the game, like the Awaken step. This mechanic allows players to utilize their resources strategically while also encouraging careful planning about when to exhaust their cards, as doing so limits their options for that turn.

The other options refer to different mechanics in the game, including discarding cards, applying penalties, or drawing cards, but they do not accurately capture the action of exhausting a card, which is specifically focused on the tapping mechanism involved in gameplay.