• oroto-norse,
• lroto-norse,
• -roto-norse,
• 0roto-norse,
• peoto-norse,
• pdoto-norse,
• pfoto-norse,
• ptoto-norse,
• p5oto-norse,
• p4oto-norse,
• prito-norse,
• prkto-norse,
• prlto-norse,
• prpto-norse,
• pr0to-norse,
• pr9to-norse,
• proro-norse,
• profo-norse,
• progo-norse,
• proyo-norse

The adjective form of the word "proto-Norse" is "proto-Norse". It remains the same in both noun and adjective forms.

The plural form of the word "proto-norse" is also "proto-norse".

The singular form of the word "proto-norse" is "proto-norse". The word does not change in its singular form.