thoughtful

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Given to careful thought; reflective.
• adjective Engrossed in thought.
• adjective Exhibiting or characterized by careful thought.
• adjective Having or showing heed for the well-being or happiness of others and a propensity for anticipating their needs or wishes.

from The Century Dictionary.

• Occupied with thought; engaged in or disposed to reflection; contemplative; meditative.
• Characterized by or manifesting thought; pertaining to thought; concerned with or dedicated to thought.
• Mindful, as to something specified; heedful; careful: followed by of or an infinitive.
• Showing regard or consideration for others; benevolent; considerate; kindly.
• Full of care; anxious; troubled.
• Synonyms Reflective, pensive, studious.
• Considerate, regardful.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Full of thought; employed in meditation; contemplative.
• adjective Attentive; careful; exercising the judgment; having the mind directed to an object.
• adjective Anxious; solicitous; concerned.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Demonstrating thought or careful consideration.
• adjective Demonstrating kindness or consideration for others.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective taking heed; giving close and thoughtful attention
• adjective having intellectual depth
• adjective acting with or showing thought and good sense
• adjective exhibiting or characterized by careful thought
• adjective considerate of the feelings or well-being of others