When it comes to synonyms for the phrase "board over," there are several options to choose from. One popular term is "cover up," which suggests a desire to hide or conceal something. Another possibility is "seal off," which implies a need to block access or prevent entry to a particular area or object. Yet another option is "plank up," which refers specifically to the act of nailing wooden boards to a surface in order to create a solid barrier or partition. Ultimately, the choice of synonym will depend on the context in which it is being used and the specific shades of meaning that the speaker or writer wishes to convey.