obstruction vs obstructer

obstruction and obstructer both are nouns.

Word	Noun	Adjective	Verb	Adverb
obstruction	Yes	No	No	No
obstructer	Yes	No	No	No

As nouns, obstruction and obstructer are synonyms defined as:

Other synonyms of obstruction include impediment, impedimenta, obstructor.

obstruction (noun)	obstructer (noun)
getting in someone's way	any structure that makes progress difficult
the act of obstructing	someone who systematically obstructs some action that others want to take
any structure that makes progress difficult
something immaterial that stands in the way and must be circumvented or surmounted
the physical condition of blocking or filling a passage with an obstruction