Where does the world lent come from?

The best answer is the Italian Word for (Slow) and this was/is used on Marine telegraphs- in one form the four power settings were ( avanti assumed) Lentissimo ( dead slow) Lento ( slow) Mezzo ( half) and Tutti ( Full speed) an alternate theory has it comes from the German Word Lenz for Spring. I"ll stand by the Slow speed setting!