Rabi Akiva holds it’s d’rabbonon. Machlokes Rishonim whether the Chachomim agree or hold it’s d’Oraisa.
M’mareach is a toldah of m’machek. Calling the normal application of ChapStick kilachar yad does not make any sense (although further research needed if there are any opinions out there that it’s not d’Oraisa anyhow).