• habachi,
• hitech,
• hibatchi,
• hitatchi,
• hirachy,
• hitchai,
• itachi,
• hitch,
• hitchy,
• inachiz,
• inachix,
• hitchi,
• chivachi,
• gitachi,
• bitachi,
• nitachi,
• jitachi,
• uitachi,
• yitachi,
• ectachia

The adjective form of the word "Hitachi" would be "Hitachian".

The plural form of the word "Hitachi" is also "Hitachi." The word is the same in both singular and plural form.

The singular form of the word "Hitachi" remains the same. The word does not change when used in singular or plural form.