Definition of "atop"
atop
preposition
Quotations
For example, when trailers containing new automobiles were first piggybacked two areas of potential damage became evident: (1) diesel locomotive exhaust left a film of oil on the new autos; and (2) auto windshields could be scarred or cracked by the metal-tipped "tell-tales" which warn men atop trains of oncoming bridges or tunnels.
1960 November, David Morgan, “"Piggyback"—U.S. success story”, in Trains Illustrated, page 684
adverb
not comparable
(literary or archaic) On, to, or at the top.
Quotations
He has a handsome face, still bearded in the midst of a mostly clean-shaving nation, and with the white hairs prevalent on the cheeks and temples; his head is bald atop, though hardly from the uneasiness of wearing a crown.
1909, William Dean Howells, Seven English Cities, Kessinger Publishing, published 2004, page 46