viscous vs gummy

viscous and gummy both are adjectives.

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

As adjectives, viscous and gummy are synonyms defined as:

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

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