weird sister vs Norn

weird sister and Norn both are nouns.

Word	Noun	Adjective	Verb	Adverb
weird sister	Yes	No	No	No
Norn	Yes	No	No	No

As nouns, weird sister and Norn are synonyms defined as:

weird sister and Norn: (Norse mythology) any of the three goddesses of destiny; identified with Anglo-Saxon Wyrd; similar to Greek Moirae and Roman Parcae

weird sister (noun)	Norn (noun)
(Norse mythology) any of the three goddesses of destiny; identified with Anglo-Saxon Wyrd; similar to Greek Moirae and Roman Parcae	(Norse mythology) any of the three goddesses of destiny; identified with Anglo-Saxon Wyrd; similar to Greek Moirae and Roman Parcae