A government building where customs are collected and where ships are cleared to enter or leave the country WordNet 3.0 & Open English WordNet

A custom house or customs house was traditionally a building housing the offices for a jurisdictional government whose officials oversaw the functions associated with importing and exporting goods into and out of a country, such as collecting customs duty on imported goods. Wikipedia

A building housing the offices that process the tariffs associated with importing and exporting goods Wikipedia Disambiguation

Government office building for import and export of goods Wikidata

An official building, in a port, where customs are collected and shipping is cleared for entry and exit. Wiktionary

Official building, in a port, where customs are collected and shipping is cleared for entry and exit. Wiktionary (translation)