TRESTLETREE
Etymology
Noun
trestletree (plural trestletrees)
(nautical) One of two strong bars of timber, fixed horizontally on the opposite sides of the masthead to support the crosstrees and the frame of the top.
Source: Wiktionary
Tres"tle*tree`, n. (Naut.)
Definition: One of two strong bars of timber, fixed horizontally on the
opposite sides of the masthead, to support the crosstrees and the
frame of the top; -- generally used in the plural. Totten.
Source: Webster’s Unabridged Dictionary 1913 Edition