Title: A Telerin Riddle
Fandom: Silmarillion
Challenge: Clue
Other prompt: N/A
Rating: G
Length: 56
Content notes: N/A
Author notes: Thanks go to Zana, Morgynleri & Runa for encouragement & sanity-checking.
Summary: Sails contain clues




Rope right through me fastens, holding fast
While I the belling belly do maintain
With knotted fingers As breath around us swirls,
the rocking wooden bed does dance through foaming lace,
While I run up and down, white wings on trees
Now stepped and rooted in no ground

Who am I? No other clue I'll give.

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Answer: Clew, (sometimes also spelled clue) which is the lower corner or corners of a sail, adjusted with ropes, used to control size and sometimes angle.