Antonyms of adj 20th

1 sense of 20th

Sense 1
twentieth, 20th -- (coming next after the nineteenth in position)

INDIRECT (VIA ordinal) -> cardinal -- (being or denoting a numerical quantity but not order; "cardinal numbers")

Similarity of adj 20th

1 sense of 20th

Sense 1
twentieth, 20th -- (coming next after the nineteenth in position)
       => ordinal (vs. cardinal) -- (being or denoting a numerical order in a series; "ordinal numbers"; "held an ordinal rank of seventh")