noun
domestic product
Refers to goods produced within one's own country, as opposed to imports. Often used in economic or trade contexts.
この店では内国産の野菜だけを売っている。
This store sells only domestically produced vegetables.
輸入品 means 'imported goods', the direct opposite of 内国産.
Compound of 内国 (ないこく, 'domestic, within the country') + 産 (さん, 'product, produce'). The exact historical derivation is uncertain, but the word follows a standard Sino-Japanese pattern for describing origin of goods.