• 国際こくさい — international
• 交際こうさい — association; socializing
• 実際じっさい — reality; actual
• 際限さいげん — limit; bounds
• 水際みずぎわ — water’s edge; shoreline
• この際さい — on this occasion

際 combines 阝 (kozato-hen, hill/place) with a phonetic element indicating boundary or side. It expresses the idea of a border or edge — both physically (水際, “water’s edge”) and abstractly (この際, “on this occasion”).