A tree sapling is an immature tree with a slender trunk. Depending on the species of tree, a sapling can be between three and 15 years old, and range in height from 2 to 10 feet (about 0.61 to 3.05 m). Saplings differ from seedlings, which are trees that are less than three years old. A sapling is a young tree, usually with a slender trunk and branches. Learn the origin, synonyms and antonyms of the word sapling, and see how it is used in literature and botany. A sapling is a young tree. Learn how to say it, see pictures and example sentences, and find synonyms and grammar notes in the Oxford Advanced Learner's Dictionary. The meaning of SAMPLING is the act, process, or technique of selecting a suitable sample; specifically : the act, process, or technique of selecting a representative part of a population for the purpose of determining parameters or characteristics of the whole population. How to use sampling in a sentence.