To see a thumb in your dream indicates that you need to get a grip on things. It is symbolic of power and ability. If you are giving the thumbs up, then it represents approval and that you are “okay” to proceed. If you are giving the thumbs down, then it means disapproval.
To dream that you have no thumb denotes poverty and loneliness.
To dream that you have an abnormally large thumb signifies a rapid rise to success.
To dream that your thumb has a very long nail signifies that some negative force is luring you toward some illicit activity.