two-faced vs double-tongued

two-faced and double-tongued both are adjectives.

Word	Noun	Adjective	Verb	Adverb
two-faced	No	Yes	No	No
double-tongued	No	Yes	No	No

As adjectives, two-faced and double-tongued are synonyms defined as:

two-faced and double-tongued: marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another

Other synonyms of two-faced include ambidextrous, deceitful, double-dealing, double-faced, duplicitous, Janus-faced.

two-faced (adjective)	double-tongued (adjective)
marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another	marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another
having two faces--one looking to the future and one to the past