The word "痴痴" is formed by duplicating the character "痴", which is a phono-semantic compound composed of the semantic radical "疒" (indicating sickness or abnormality) and the phonetic component "知" (providing historical pronunciation cues), together conveying the core meaning of foolishness or infatuation; this reduplication modifies the meaning to function as an adverb or adjective describing a state of being foolishly dazed or intently focused.