Icelandic

Suffix

-inn m ‎(feminine -in, neuter -ið)

1. marks definiteness of a noun; the

   Maðurinn er hávaxinn.‎ ― The man is tall.

   Ég elska barnið mitt.‎ ― I love my child.

   Hvar er hesturinn minn?‎ ― Where is my horse?

Old Norse

Etymology

From Proto-Norse *-īna-, from Proto-Germanic *-īnaz. Originally, this suffix was used to create adjectives that refer to materials, such as Old Norse eikinn ‎(“oaken”), from eik ‎(“oak”) and gullinn ‎(“golden”), from gull ‎(“gold”). Later, use of this suffix was extended to create adjectives from verbs, such as Old Norse lyginn ‎(“prone to lying”), from ljúga ‎(“to lie”).^[1]

Suffix

-inn m, -in f, -it n

1. suffix used to create adjectives from nouns and verbs

References

1. ↑ Ragnvald Iversen, Norrøn grammatikk, sjette rev. utg. 1961; p. 208