noun
international character; internationalism; cosmopolitanism
Refers to the quality of being international, globally oriented, or cosmopolitan. Often used in discussions of culture, organizations, or personal outlook.
この大学は国際性を重視している。
This university emphasizes its international character.
彼の考え
You can sense a cosmopolitan outlook in his way of thinking.
国際化 means 'internationalization' (the process of becoming international), whereas 国際性 is the resulting state or quality.
Compound of 国際 (international) + 性 (-ness, -ity). A straightforward Sino-Japanese formation.