This is the 9355th most frequent Russian word.
таможенному
"To the customs" (dative case of "таможенный").
The word 'таможенному' is in dative case, agreeing with the noun 'инспектору' to specify the recipient of the action.
Мы обратились к таможенному инспектору за помощью.
We approached the customs inspector for assistance.
The word 'таможенному' modifies 'делу,' indicating that the affair is related to customs service.
Этот вопрос относится к таможенному делу.
This issue pertains to customs affairs.
The word 'таможенному' describes the noun 'закону,' specifying that the law is connected with customs regulations.