log1
  
  n.
   - a part of the trunk or a large branch of a tree that has fallen or been cut off.
 - 
(also logbook)
 an official record of events during the voyage of a ship or aircraft.
 - an apparatus for determining the speed of a ship, originally one consisting of a float attached to a knotted line.
 
v.
 (logs, logging, logged)
   - enter (something) in a log. 
▸achieve (a certain distance, speed, or time).
 - 
(log in/on or off/out)
 go through the procedures to begin (or conclude) use of a computer system.
 - cut down (an area of forest) to exploit the wood commercially.
 
 
  Derivative
  
  History
  Log is a Middle English word of obscure origin. The link between the original sense of the noun, ‘a part of a tree that has fallen or been cut off’, and the verb ‘enter something in a log’ is found in sense 3 of the noun, ‘an apparatus for determining the speed of a ship’. This originally consisted of a ‘log’ or wooden float attached to a very long knotted line; the log was tossed overboard and the length of line run out in a certain time was used as an estimate of the vessel's speed. From here came the notion of a ship's journal or logbook, in which a detailed daily record of a voyage was entered, and so the verb developed. See also knot1.