The word "twofacedness" suggests someone who is deceitful or insincere. Some synonyms for this term include duplicity, double-dealing, deceitfulness, deception, and hypocrisy. "Duplicity" suggests a deliberate and deceitful two-faced behavior, while "double-dealing" means to deceive and do something underhanded. "Deceitfulness" implies a constant practice of lying, while "deception" is the act of being dishonest and misleading. Lastly, "hypocrisy" is used to describe someone who pretends to have high moral standards but acts contrary to them. All of these synonyms are variations of the same underlying concept, and each highlights the negative character attributes of someone who portrays twofacedness.