The noun has one meaning:
Meaning #1:
acting in bad faith; deception by pretending to entertain one set of intentions while acting under the influence of another
Synonym: duplicity
The adjective double-dealing has one meaning:
Meaning #1:
marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another
Synonyms: ambidextrous, deceitful, duplicitous, Janus-faced, two-faced, double-faced, double-tongued
