The Collaborative International Dictionary
Leech line
Leech \Leech\, n. [Cf. LG. leik, Icel. l[=i]k, Sw. lik boltrope, st[*a]ende liken the leeches.] (Naut.) The border or edge at the side of a sail. [Written also leach.]
Leech line, a line attached to the leech ropes of sails,
passing up through blocks on the yards, to haul the
leeches by.
--Totten.
Leech rope, that part of the boltrope to which the side of a sail is sewed.
Wiktionary
leech line
alt. (context nautical English) A line for tightening the leech of a triangular mainsail to prevent it from fluttering. n. (context nautical English) A line for tightening the leech of a triangular mainsail to prevent it from fluttering.