wistful (adj.)

• ashamed
• atrabilious
• blue
• cogitative
• cognitive
• conceptive
• conceptual
• conscience-smitten
• contemplative
• deliberative
• funky
• homesick
• introspective
• meditative
• melancholic
• melancholy
• mental
• musing
• noetic
• nostalgic
• pensive
• pondering
• prehensive
• reflecting
• reflective
• regretful
• remorseful
• rueful
• ruminant
• ruminative
• serious
• shamefaced
• shameful
• sober
• sorry
• speculative
• thinking
• thought
• thoughtful
• wishful