noun which may take the genitive case particle 'no', noun
worldwide; universal; common to all countries
Used to describe something that is the same or understood everywhere in the world, often with a nuance of being a shared standard or experience.
笑顔は万国共通のコミュニケーション手段だ。
A smile is a universal means of communication.
このルールは万国共通ではない。
This rule is not common to all countries.
国際的 means 'international' and focuses on relations between nations, while 万国共通 emphasizes something being the same across all countries.
普遍的 is more abstract and philosophical, meaning 'universal' in a timeless or absolute sense, whereas 万国共通 is more concrete and often used for practical, cross-cultural commonalities.
Compound of 万国 (all countries) and 共通 (common, shared). The exact historical derivation is uncertain, but the word is a straightforward Sino-Japanese compound.