Synonym for cheerful is "light-hearted"

blissful [adjective]

means "glad"
happy, blithe, cheerful, contented, delighted, gay

breezy [adjective]

means "happy"
light-hearted, jaunty, sprightly, gay, cheerful, cheery

bright [adjective]

means "characteristic"
lively, brisk, animated, serene, cheerful, gay

- translate bright

cheery [adjective]

means "happy"
light-hearted, jaunty, sprightly, gay, cheerful, breezy

gay [adjective]

means "character trait"
cheerful, happy, convivial, frolicsome, good-humoured, jovial

genial [adjective]

means "friendly"
pleasant, agreeable, cheerful, cordial, hearty, well-disposed

glad [adjective]

means "property"
bright, happy, joyful, joyous, cheerful, light

happy [adjective]

means "feeling"
glad, blissful, blithe, cheerful, contented, delighted

- translate happy

hearty [adjective]

means "warm and friendly"
warm, cheerful, enthusiastic, genial, sincere, zealous

jolly [adjective]

means "happy"
joyous, merry, cheerful, glad, gay, jovial

light [adjective]

means "feeling"
happy, carefree, cheerful, cheery, gay, light-hearted

light-hearted [adjective]

means "happy"
cheerful, jolly, merry, buoyant, spirited, lively

pretty [adjective]

means "property"
pleasant, excellent, delightful, fine, cheerful, splendid

ready [adjective]

means "character trait"
ardent, cheerful

rebounding [adjective]

means "resilient"
elastic, springy, flexible, buoyant, cheerful

resilient [adjective]

means "rebounding"
elastic, springy, flexible, buoyant, cheerful

sanguine [adjective]

means "gladdening"
cheerful

well-disposed [adjective]

means "friendly"
pleasant, agreeable, cheerful, cordial, hearty, genial

whole-hearted [adjective]

means "generous"
resilient, hearty, robust, ungrudging, optimistic, cheerful

cheerfulness [noun]

means "good humour"
gaiety, happiness, buoyancy, cheer, light-heartedness

buoyancy [noun]

means "good humour"
gaiety, happiness, cheerfulness, cheer, light-heartedness

cheer [noun]

means "entertainment"
gaiety, animation, cheerfulness, delight, fun, gladness

elation [noun]

means "hopefulness"
cheerfulness, happiness, brightness, enthusiasm, optimism, exhilaration

exhilaration [noun]

means "hopefulness"
cheerfulness, happiness, brightness, enthusiasm, elation, optimism

geniality [noun]

means "friendliness"
cheerfulness, warmth, kindliness, benevolence, happiness

gladness [noun]

means "gaiety"
animation, cheerfulness, delight, fun, cheer, glee

glee [noun]

means "gaiety"
animation, cheerfulness, delight, fun, gladness, cheer

merriment [noun]

means "gaiety"
animation, cheerfulness, delight, fun, gladness, glee

mirth [noun]