A medical procedure used in prenatal diagnosis of genetic risk factors.
(Of a boat) Toward the stern.
(nautical, aeronautical) situated at or toward the stern or tail
at or near or toward the stern of a ship or tail of an airplane; "stow the luggage aft"; "ships with square sails sail fairly efficiently with the wind abaft"; "the captain looked astern to see what the fuss was about"
at or near or toward the stern of a ship or tail of an airplane
