''Very interesting . . .''

• "Let me think ..."
• What you might say after reading a tricky crossword clue
• Thoughtful interjection
• 'Let me think, ....'
• "I'm thinking ..."
• 'Very interesting'
• "Let me see . . ."
• "Interesting ..."
• Sound of deliberation

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
representative of a sound made during contemplation or showing mild disapproval, attested from 1868, but this is probably a variation of the hum attested in similar senses from 1590s.