The crossword solution for the term 'NONE TOO BRAINY' is 'DENSE', which is a five-letter word. DENSE is an adjective that means having a high concentration of something, such as people or objects, in a given area or space. It can also be used to describe someone who is not very intelligent or quick to understand. Therefore, the phrase 'NONE TOO BRAINY' can be used to describe someone who is not very smart.