This is the 283rd most frequent Turkish word.
başında
"Başında" means "at the beginning of" or "on/at (someone's) head" depending on context.
Here, 'başında' implies a position or location, indicating where the tree is situated.
Evin başında büyük bir ağaç var.
There is a big tree at the top of the house.
In this sentence, 'başında' refers to the start or the beginning of the event, indicating a temporal context.
Olayın başında her şey oldukça sakin görünüyordu.
At the beginning of the event, everything seemed quite calm.
This usage of 'başında' denotes a temporal beginning, relating to the early time of the day.