obstructer vs obstacle

obstructer and obstacle both are nouns.

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

As nouns, obstacle is a hyponym of obstructer; that is, obstacle is a word with a more specific, narrower meaning than obstructer:

obstructer: any structure that makes progress difficult
obstacle: an obstruction that stands in the way (and must be removed or surmounted or circumvented)

obstructer (noun)	obstacle (noun)
any structure that makes progress difficult	an obstruction that stands in the way (and must be removed or surmounted or circumvented)
someone who systematically obstructs some action that others want to take	something immaterial that stands in the way and must be circumvented or surmounted