p (nautical) behind | Behind; toward the stern relative to some other object or position; aft of. (defdate|First attested around the late 15th century.)
a (nautical|obsolete) Backwards. (defdate|Attested from around (1150 to 1350) until the late 15th century.)(reference-book | last =| first = | authorlink = | coauthors = | editor =Brown, Lesley | others = | title = The Shorter Oxford English Dictionary | origdate = | origyear = 1933| origmonth = | url = | format = | accessdate = | accessyear = | accessmonth = | edition = 5th | date = | year =2003| month = | publisher =Oxford University Press | location =Oxford, UK | language = | id = | doi = | isbn =978-0-19-860575-7 | lccn = | ol = | pages =2| chapter = | chapterurl = | quote =)