A keyhole can symbolize our tentative entry into the Sublime or transcendent state. Our vision is somewhat restricted and even in dreams we do not yet have confidence to remain in that state, but must accept the need to remain grounded. Since a key usually requires a keyhole, to dream of one without the other indicates some kind of confusion between the inner and outer self. A keyhole by itself can represent gossip or treachery by a close associate. When we dream that we are peering through a keyhole, we are conscious of the fact that our ability to see and understand is somehow impaired. Conventionally, the keyhole has been taken to represent the feminine, so that impairment could result from our attitude to the feminine and to feminine qualities such as intuition. When a woman dreams of a keyhole without the key she will be conscious of her own vulnerability. In a man's dream he will need to look at the sensitivities of people around him. Not being able to find the keyhole suggests he has not yet quite understood those sensitivities either in personal or work relationships. You might also like to consult the entries for Key and Lock.