Antonyms of adj twisty

1 sense of twisty

Sense 1
tortuous, twisting, twisty, winding, voluminous -- (marked by repeated turns and bends; "a tortuous road up the mountain"; "winding roads are full of surprises"; "had to steer the car down a twisty track")

INDIRECT (VIA crooked) -> straight -- (having no deviations; "straight lines"; "straight roads across the desert"; "straight teeth"; "straight shoulders")

Similarity of adj twisty

1 sense of twisty

Sense 1
tortuous, twisting, twisty, winding, voluminous -- (marked by repeated turns and bends; "a tortuous road up the mountain"; "winding roads are full of surprises"; "had to steer the car down a twisty track")
       => crooked (vs. straight) -- (having or marked by bends or angles; not straight or aligned; "crooked country roads"; "crooked teeth")