What is tacit approval?

Tacit approval is a benign form of approval that is not expressed clearly, in words. It is silent approval. It is approval that is implied by other statements, actions or by a failure to clearly express disapproval with the situation, performance, idea, plan or request. Tacit approval may be expressed by body language such as smiling, a nod of the head, a pat on the back or a shrug of the shoulders. It can be a friendly form of encouragement and support. On the other hand it is approval that can be easily and conveniently denied as/if a situation deteriorates.