Antonyms of adv perceptibly

1 sense of perceptibly

Sense 1
perceptibly, noticeably, observably -- (in a noticeable manner; "he changed noticeably over the years")
       Antonym of imperceptibly (Sense 1)
      => imperceptibly, unnoticeably -- (in an imperceptible manner or to an imperceptible degree; "the power of the Secretary of State in London increased gradually but imperceptibly")

Synonyms of adv perceptibly

1 sense of perceptibly

Sense 1
perceptibly, noticeably, observably -- (in a noticeable manner; "he changed noticeably over the years")