We don't have synonyms for check bit yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are check in, check out and chick lit.
(n) :
(computer science) abit that is used in an error detection procedure in which a 0 or 1 is added to each group of bits so that it will have either an odd number of 1's or an even number of 1's; e.g., if the parity is odd then any group of bits that arrives with an even number of 1's must contain an error
(n) :
(computer science) abit that is used in an error detection procedure in which a 0 or 1 is added to each group of bits so that it will have either an odd number of 1's or an even number of 1's; e.g., if the parity is odd then any group of bits that arrives with an even number of 1's must contain an error