The Collaborative International Dictionary of English v.0.48:
Heedful \Heed"ful\, a. Full of heed; regarding with care; cautious; circumspect; attentive; vigilant. --Shak. -- Heed"ful*ly, adv. -- Heed"ful*ness, n. [1913 Webster]WordNet (r) 3.0 (2006):
heedfulness n 1: the trait of staying aware of (paying close attention to) your responsibilities [syn: mindfulness, heedfulness] [ant: heedlessness, inadvertence, inadvertency, unmindfulness]