Someone who's jolly is extremely cheerful. Your jolly French teacher might spend a large part of each class laughing out loud at his own jokes — if only you understood French, you could laugh along with him.

Pronunciation: /'dʒɑli/
English description: full of or showing high-spirited merriment
Synonyms: merry
Chinese Translation: 愉快的(yu2 kuai4 de)
Spanish Translation: alegre
ORIGIN: Santa Claus might be the mythical figure best known for being jolly — he's especially famous for his jolly "Ho ho ho!" Anyone who tends to be merry or festive is jolly, and when you want to cheer up a less-than-jolly friend, you can jolly them, teasing or kidding until they smile. The Old French root is jolif, "festive, merry, or pretty.".

EXAMPLE SENTENCE:

In Hollywood, the Jolly Old Elf has a serious dark side on occasion and that is represented in the supercut, too.
Notice that he manages to maintain his jolly equanimity even when being vilified.

*New word description, story and part of "EXAMPLE SENTENCE" are cited in Vocabulary.com