• zrkansas river,
• srkansas river,
• wrkansas river,
• qrkansas river,
• aekansas river,
• adkansas river,
• afkansas river,
• atkansas river,
• a5kansas river,
• a4kansas river,
• arjansas river,
• armansas river,
• arlansas river,
• aroansas river,
• ariansas river,
• arkznsas river,
• arksnsas river,
• arkwnsas river,
• arkqnsas river,
• arkabsas river

The adjective form of the word "Arkansas River" is "Arkansas Riverian".

The plural form of "Arkansas River" is "Arkansas Rivers".

The singular form of the word "Arkansas River" is still "Arkansas River". The word itself is a proper noun and refers to a specific river in the United States.