1. Taking heed; giving close and thoughtful attention
   "heedful of the warnings"; "so heedful a writer"; "heedful of what they were doing"
   - attentive, thoughtful, paying attention 
2. Cautiously attentive
   "heedful of his father's advice"
   - careful 
3. Giving attention
   - advertent

See also: attentive, attentiveness, aware, heed, heedfully, heedfulness, mindful, paying attention, regard

Antonym: heedless

• in due season
• in due time
• in earnest
• in effect
• in essence
• in everyone's thoughts
• in evidence
• in extremis
• in fact
• in fiscal matters
• in flagrante delicto
• in flight
• in for
• in force
• in front
• in full
• in full action
• in full swing
• in full view
• in gear
• in general
• in good order
• in good spirits
• in good taste
• in good time