Ben Sira vs Sirach

Ben Sira and Sirach both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ben Sira	Yes	No	No	No
Sirach	Yes	No	No	No

As nouns, Ben Sira and Sirach are synonyms defined as:

Ben Sira and Sirach: an Apocryphal book mainly of maxims (resembling Proverbs in that respect)

Other synonyms of Ben Sira include Ecclesiasticus, Wisdom of Jesus the Son of Sirach.

Ben Sira (noun)	Sirach (noun)
an Apocryphal book mainly of maxims (resembling Proverbs in that respect)	an Apocryphal book mainly of maxims (resembling Proverbs in that respect)