To open, unwind, or unroll (what is wrapped or wound); †to unfurl (a sail). Also figurative.

to let fly v. Nautical. To allow (a sail or sheet) to fly loose; rarely to set (a sail), to carry, hoist (colours).

transitive. To open or spread out (a flag or sail) to the wind.

To roll down; to cause to descend with rolling motion; also to unroll (something rolled up), to unfurl (a sail). archaic.

Nautical. transitive. To free and shake out (a flag or sail which has been furled); also with out.