Whistly adv.

arch. [f. WHIST a.¹ + -LY².] Silently, quietly, softly, without noise.

a. 1400–50.  Wars Alex., 1851. Off þe whele of forton & þe whene þat whistely chaungez.

1592.  Arden of Feversham, III. iii. 9. I vppon a little rysing hill Stoode whistely watching for the herds approch.

1854.  Syd. Dobell, Balder, xxviii. 192. ‘Whistly, whistly,’ said she:… ‘He must not wake.’