The word Ashdodi (אַשְׁדּוֹדִי) is a gentilic adjective — the demonym for a person from Ashdod. It appears in Nehemiah 4:7 where the Ashdodites joined in opposing the rebuilding of Jerusalem's walls, and in Nehemiah 13:23 where some Israelite men had married Ashdodite women whose children could not speak Hebrew.
The brief mention of Ashdodites in Nehemiah carries significant theological weight on covenant identity and cultural preservation. Nehemiah's grief over children who could not speak Hebrew was concern that the language of covenant and Scripture was being lost. The Torah, Psalms, and Prophets were in Hebrew; a generation that could not read Hebrew was cut off from God's word. The Ashdodites' opposition to Jerusalem's wall also illustrates that those outside the covenant community often perceive the strengthening of God's people as a threat.