Antonyms of adj gradational

1 sense of gradational

Sense 1
gradational, gradatory, graduated -- (taking place by degrees)

INDIRECT (VIA gradual) -> sudden -- (happening without warning or in a short space of time; "a sudden storm"; "a sudden decision"; "a sudden cure")

Similarity of adj gradational

1 sense of gradational

Sense 1
gradational, gradatory, graduated -- (taking place by degrees)
       => gradual (vs. sudden) -- (proceeding in small stages; "a gradual increase in prices")