'sapling' originates from Middle English, from the element 'sap' plus the diminutive suffix '-ling', where 'sap' referred to the sap or a young shoot and '-ling' meant 'young' or 'small'.

'sap' itself goes back to Old English (recorded as 'sæp' or similar), and the compound form appeared in Middle English (c. 14th century) as 'sapling', which developed into the modern English 'sapling'.

Initially it meant 'a young shoot or young tree', and this primary meaning has largely remained; over time it also gained a figurative sense meaning 'an inexperienced person'.