http://www.thefreedictionary.com/unidirectional http://www.thefreedictionary.com/unidirectional unidirectional unidirectional unidirectional unidirectional unidirectional http://www.thefreedictionary.com/unidirectional http://www.thefreedictionary.com/unidirectional http://www.thefreedictionary.com/unidirectional unidirectional unidirectional unidirectional http://www.thefreedictionary.com/unidirectional http://www.thefreedictionary.com/unidirectional