tūpono - to come upon accidentally, happen by chance
Tūpono, v.t. Light upon accidentally, chance to hit. Tupono pu te rakau ki te kanohi o te tamaiti.—Tupono atu ki te riri, whati ana te hoariri (W. iv, 49).
Williams Dictionary
Nō tō tāua taenga, ka tūpono ia e mau kaka rerehua ana rāua.When they arrived, he realised that they were wearing fancy dress.Belonging to the past - nō