This is the 801st most frequent Japanese word.
都
"Metropolis," "capital," or "city."
In this sentence, '都' refers to a capital city.
東京は日本の都です。
Tokyo is the capital of Japan.
Here, '都合' (tsugou) uses '都' to represent 'condition' or 'situation'.
都合が悪い場合は教えてください。
Please let me know if it is inconvenient for you.
In this usage, '都' means a large city or metropolis.