From The Collaborative International Dictionary of English v.0.48 :
Taffrail \Taff"rail\, n. [D. tafereel a panel, picture, fr.
tafel table, fr. L. tabula. See Table.] (Naut.)
The upper part of a ship's stern, which is flat like a table
on the top, and sometimes ornamented with carved work; the
rail around a ship's stern. [Written also tafferel.]
[1913 Webster]
From WordNet (r) 3.0 (2006) :
taffrail
n 1: the railing around the stern of a ship