Definition of overtop:
(v) :
(transitive) To be higher than; to rise over the top of.
(adv) :
(now chiefly Canada, US) Over the top.
(v) :
(transitive) To place too many toppings on.
(n) :
(clothing) A garment designed to be worn over the top portion of other clothes, such as an overshirt, vest, or overtunic.