Antonyms of adj mirthless

1 sense of mirthless

Sense 1
mirthless -- (lacking mirth)

INDIRECT (VIA joyless) -> joyous -- (full of or characterized by joy; "felt a joyous abandon"; "joyous laughter")

Similarity of adj mirthless

1 sense of mirthless

Sense 1
mirthless -- (lacking mirth)
       => joyless (vs. joyous) -- (not experiencing or inspiring joy; "a joyless man"; "a joyless occasion"; "joyless evenings")