The word 'biplicity' is not commonly used in everyday language. It is a noun that means "the state of being double or twofold". Synonyms for 'biplicity' could include 'duality', 'ambivalence', 'divisiveness', 'duplication', or 'dichotomy'. 'Duality' refers to the quality or state of being two or having two parts. 'Ambivalence' describes an emotional state of being uncertain or conflicted between two options. 'Divisiveness' refers to something that tends to create division or separation. 'Duplication' means something that is an exact copy of something else. Finally, 'dichotomy' refers to a division or contrast between two things that are completely different.