Impressionable means easily influenced by others. An impressionable age, young and impressionable, impressionable minds.
It is used almost entirely about the young, and at an impressionable age is the fixed phrase. The image behind it is wax: something soft enough to take an impression, which is a fair description of how learning works at any age.
1adjectiveimpressionableEasily influenced by others.
“Violent films can have a bad influence on impressionable young children.”
impressionable is a quality.
French impressionnable comes from impression, from Latin imprimere, to press into.
French
impressionnable
English, today
impressionable
From French impressionnable. From French impressionnable, equivalent to impression + -able. See also impressible.
Etymology from Wiktionary, CC BY-SA