• statline,
• stateline,
• ztate line,
• xtate line,
• dtate line,
• etate line,
• wtate line,
• srate line,
• sfate line,
• syate line,
• s6ate line,
• s5ate line,
• stzte line,
• stste line,
• stwte line,
• stqte line,
• stare line,
• stafe line,
• stage line,
• staye line

The adjective form of "state line" is "interstate".

The plural form of "state line" is "state lines".

The singular form of the word "state line" is "state line". Both the singular and plural forms of the word remain the same.