The process of unconscious learning, occuring only through constant exposure. Usually happens very slowly. A person who moves into a new region may acquire an accent this way, or a repertoire of slang. A person immersed in a culture speaking a language foreign to them will eventually pick up bits and pieces, even becoming fluent after a while. Someone who reads a large amount of well-written books will acquire a broader vocabulary. Unfortunately, a person can also acquire bad habits through mental osmosis as well.