notion

a vague idea in which some confidence is placed; "his impression of her was favorable"; "what are your feelings about the crisis?"; "it strengthened my belief in his sincerity"; "I had a feeling that she was lying"

a general inclusive concept

an odd or fanciful or capricious idea; "the theatrical notion of disguise is associated with disaster in his stories"; "he had a whimsy about flying to the moon"; "whimsy can be humorous to someone with time to enjoy it"

(usually plural) small personal articles or clothing or sewing items; "buttons and needles are notions"