sand viper vs horned viper

sand viper and horned viper both are nouns.

Word	Noun	Adjective	Verb	Adverb
sand viper	Yes	No	No	No
horned viper	Yes	No	No	No

As nouns, sand viper and horned viper are synonyms defined as:

sand viper and horned viper: highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye

Other synonyms of sand viper include cerastes, Cerastes cornutus, horned asp.

sand viper (noun)	horned viper (noun)
highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye	highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye
harmless North American snake with upturned nose; may spread its head and neck or play dead when disturbed