Antonyms of adj steep-sided

1 sense of steep-sided

Sense 1
steep-sided -- (having very steep sides)

INDIRECT (VIA steep) -> gradual -- ((of a topographical gradient) not steep or abrupt; "a gradual slope")

Similarity of adj steep-sided

1 sense of steep-sided

Sense 1
steep-sided -- (having very steep sides)
       => steep (vs. gradual) -- (having a sharp inclination; "the steep attic stairs"; "steep cliffs")