|From Little and Graves (2008)|
L = average number of items in the queuing system,
(equivalent to WIP in Kanban terminology)
W = average waiting time in the system for an item,
(equivalent to System Lead Time)
λ = average number of items arriving per unit time
(equivalent to Delivery Rate, assuming "stationarity")
With Kanban preferred terms we can see this maps to:
WIP = Delivery Rate * Lead Time
Delivery Rate = WIP / Lead Time
Little used "waiting time" for the time taken by one unit to traverse the system (W) because his original context was queuing systems. For other applications he suggested Flow Time, which I think is a very useful alternative.
He also notes though that other authors use other terms for W, including cycle time, throughput time, and sojourn time, depending on the context. Yes - cycle time I'm afraid is in that list which is why confusion still abounds. This conflicts with the more generally accepted definition of cycle time in manufacturing, which corresponds to the target rate of working expressed as Takt Time, and is the reciprocal of Delivery Rate. In other words this confusion of terminology is at least as old as the reference Little and Graves cite: Factory Physics by Hopp and Spearman (1st edition:1996).
Useful background, but the message to me is still: "Don't use Cycle Time in Kanban!".
 Little, J. D. C and S. C. Graves (2008). Little's Law, pp 81-100, in D. Chhajed and TJ. Lowe (eds.) Building Intuition: Insights From Basic Operations Management Models and Principles. doi: 10.1007/978-0-387 -73699-0, (c) Springer Science + Business Media, LLC http://web.mit.edu/sgraves/www/papers/Little%27s%20Law-Published.pdf
 Hopp, W. J. and M. L. Spearman (2000). Factory Physics: Foundations of Manufacturing Management, 2nd (ed.), Irwin McGraw Hill, New York, NY.