English word ectosymbiotic comes from English symbiotic, English ecto- (Outside.)

Detailed word origin of ectosymbiotic

Dictionary entry	Language	Definition
symbiotic	English (eng)	(astronomy) symbiotic star (ecology) Of, or relating to symbiosis; living together.. Of a relationship with mutual benefit between two individuals or organisms.
ecto-	English (eng)	Outside.
ectosymbiotic	English (eng)	Of or pertaining to ectosymbiosis or an ectosymbiont.

Words with the same origin as ectosymbiotic