Adjective
Capable of being impressed; susceptible; sensitive.
Source: Webster's dictionaryEvery man, however obscure, however far removed from the general recognition, is one of a group of men impressible for good, and impressible for evil, and it is in the nature of things that he cannot really improve himself without in some degree improving other men. Charles Dickens
an impressionable youngster Source: Internet
an impressionable age Source: Internet
a waxy mind Source: Internet