Snakily

adv. [f. SNAKY a. + -LY².] In a snaky or snake-like manner; windingly.

1870.  W. Thornbury, Tour r. Eng., I. xv. 308. The Orwell … snakily winding between flat muddy reaches.

1891.  G. Meredith, One of our Conq., III. ix. 179. Foul Furies … hissing and snakily lashing, hounding her to expulsion.