容许 (róng xǔ) is a formal verb meaning 'to permit, to allow', common in written and legal language. It is more formal than the neutral 允许 (yǔn xǔ), and similar to 许可 (xǔ kě) and 准许 (zhǔn xǔ), but 许可 often refers to official permission (e.g., a license) and 准许 to formal authorization. 容许 is frequently used in negative statements and conditional phrases like 'if time permits'.