Romance Languages:
* Spanish: Feliz
* French: Heureux/heureuse
* Italian: Felice/felice
* Portuguese: Feliz
* Romanian: Fericit/fericită
Germanic Languages:
* German: Glücklich
* Dutch: Gelukkig
* Swedish: Glad/lycklig
* Danish: Glad
* Norwegian: Glad
Slavic Languages:
* Russian: Счастливый (schastlivy)
* Polish: Szczęśliwy/szczęśliwa
* Czech: Šťastný/šťastná
* Ukrainian: Щасливий (schastlyvy)
Other Languages:
* Chinese (Mandarin): 快乐 (kuài lè)
* Japanese: 幸せ (shiawase)
* Korean: 행복 (haengbok)
* Arabic: سعيد (saʿīd)
* Hindi: खुश (khush)
* Vietnamese: Vui
* Thai: มีความสุข (mee khwam suk)
* Greek: Ευτυχισμένος (eftichimenos)
Note: This is just a small sample of languages. Many other languages have their own unique ways of expressing happiness.