gummy vs viscous

gummy and viscous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
gummy	No	Yes	No	No
viscous	No	Yes	No	No

As adjectives, gummy and viscous are synonyms defined as:

Other synonyms of gummy include gluey, glutinous, mucilaginous, pasty, sticky, viscid.

gummy (adjective)	viscous (adjective)
having the sticky properties of an adhesive	having the sticky properties of an adhesive
covered with adhesive gum	having a relatively high resistance to flow