The word "twoface" can refer to someone who is deceitful, unreliable, or two-faced. However, there are a variety of synonyms that can be used to describe this type of behavior. Some alternatives include duplicitous, treacherous, untrustworthy, sly, sneaky, and hypocritical. Other words that might come to mind include disingenuous, insincere, false, and phony. Depending on the context, one might also use terms like slippery, evasive, or conniving to describe someone who is not forthcoming or who is intentionally misleading. In any case, these synonyms all convey the sense of a person who cannot be trusted or relied upon, whether through their actions or their words.