The word "审核" is formed by combining the character "审", meaning to examine, which is composed of "宀" representing a covered space and "申" indicating extension or statement, thus implying a detailed investigation, with the character "核", meaning to verify or check, composed of "木" for tree and "亥" for the twelfth earthly branch, here used to denote the core or essential part requiring validation; together, they create a compound where "审" conveys the action of scrutiny and "核" conveys the action of cross-checking, resulting in the meaning of auditing or reviewing.