Definitions: (1) fully aware and attentive; wide awake; (2) quick to understand or respond; perceptive; (3) ready to act; watchful; vigilant; (4) moving with promptness; nimble; active; lively
Symbol: an arrowhead (American Indian)
Observation: One can train oneself to be alert to almost anything. It may, of necessity, be danger. It may, of lack, be attention. Or it may be any positive quality.