What's the difference between jocund and jocundity?

Jocund

Definition:

• () Merry; cheerful; gay; airy; lively; sportive.
• (adv.) Merrily; cheerfully.

Example Sentences:

• (1) On the Sun's marketing site, where they address the people who really matter to them, their corporate partners, they eschew the colloquial jocundity, where stars romp in love-nests and drop tots, here the silvery nomenclature of commerce reigns, the Sun's true tongue.
• (2) She's a less jocund Heather Mills dressed for Whitby Goth Weekend, the sort of mate's new girlfriend you'd rather be bummed ragged by a White Walker than let on your pub quiz team.

Jocundity

Definition:

• (n.) The state or quality of being jocund; gayety; sportiveness.

Example Sentences:

• (1) On the Sun's marketing site, where they address the people who really matter to them, their corporate partners, they eschew the colloquial jocundity, where stars romp in love-nests and drop tots, here the silvery nomenclature of commerce reigns, the Sun's true tongue.
• (2) She's a less jocund Heather Mills dressed for Whitby Goth Weekend, the sort of mate's new girlfriend you'd rather be bummed ragged by a White Walker than let on your pub quiz team.