Antonyms of adj omissible

1 sense of omissible

Sense 1
omissible -- (capable of being left out)

INDIRECT (VIA incidental) -> basic -- (pertaining to or constituting a base or basis; "a basic fact"; "the basic ingredients"; "basic changes in public opinion occur because of changes in priorities")

Similarity of adj omissible

1 sense of omissible

Sense 1
omissible -- (capable of being left out)
       => incidental (vs. basic), incident -- ((sometimes followed by `to') minor or casual or subordinate in significance or nature or occurring as a chance concomitant or consequence; "incidental expenses"; "the road will bring other incidental advantages"; "extra duties incidental to the job"; "labor problems incidental to a rapid expansion"; "confusion incidental to a quick change")