### Clue: Those spreading the gospel about old pediatrician (5)
### Answer: SPOCK 
 ### Explanation: Definition: pediatrician
**SPCK** (Society for Promoting Christian Knowledge, so "those spreading the gospel") *about* **O** (old) 
 
 
*Refers to Benjamin Spock, an American paediatrician who wrote the bestselling book, *Baby and Child Care*.