The word 充足 is formed by combining two characters with similar meanings to reinforce a single concept. 充 conveys the idea of being full, sufficient, or to fill, while 足 means foot, but in this context its ancient and enduring figurative meaning is "enough" or "adequate". When placed side-by-side, their individual notions of sufficiency and fullness merge and amplify one another, creating a compound that expresses a robust state of being plentiful, fully satisfied, or amply supplied.