すれちがい
すれちがい · surechigai · JLPT N1 · noun
brush
🚶🚶 すれ違い = 擦れ (brush against) + 違う (go different ways): two people brush past and go on their way
すれ違う means to pass each other in opposite directions. The -い ending turns it into a noun, so a chance encounter is a brief pass where you brush by someone you did not plan to meet.