The term 'Church Service Book' can be broken down into two crossword solutions: 'ORDINAL' (7 letters) and 'MISSAL' (6 letters). An ORDINAL is a type of number that indicates position or rank in a series, such as first, second, third, etc. A MISSAL is a book containing all the texts and chants necessary for the celebration of Mass throughout the liturgical year. It is used by the priest or deacon when celebrating Mass. Together, these two words form the term 'Church Service Book, ' which is a book containing the liturgy and prayers used in Christian worship services.