If i recall , it was Keith who you would need to take the direct quote from, but it was both Entwistle's and Moon's idea, it was about there new super group(previously called ''The New Yardbirds")conataining, John Entwistle, Keith Moon, Jimmy Page, and Jeff Beck. They had mentioned in a joking way that there super-group would go down like a lead zeppelin there manager then suggested to drop the A from lead so that it wouldn't be mis-pronounced as "leed" Zeppelin
-- You may have to check my facts on this, im only getting this information from a School Report i did on them last year
sorry for the topic de-railing