taking heed; giving close and thoughtful attention
"heedful of the warnings"
"so heedful a writer"
"heedful of what they were doing"
considerate of the feelings or well-being of others
"She was thoughtful enough to bring a warm sweater when she noticed I was shivering in the cold draft."
Demonstrating thought or careful consideration.
"She made a thoughtful decision to donate her inheritance to the local library after carefully weighing all the options."
In plain English: Thoughtful means thinking carefully about something before you do it to make sure everything is right.
"The thoughtful gift showed how much she cared about his interests."
Usage: Use "thoughtful" to describe considerate actions rather than the act of thinking itself, which requires "thinking." It often implies a deliberate effort to meet someone's needs, distinguishing it from merely being quiet or reflective.
Thoughtful comes from Middle English, where it was formed by adding the suffix "-ful" to "thought." The word has retained its original meaning of being full of thoughts or considerate since entering the language.