Definition of "Log" :

noun: measuring instrument that consists of a float that trails from a ship by a knotted line in order to measure the ship's speed through the water

noun: a written record of events on a voyage (of a ship or plane)

noun: a written record of messages sent or received

"They kept a log of all transmission by the radio station."

noun: the exponent required to produce a given number

noun: a segment of the trunk of a tree when stripped of branches

verb: enter into a log, as on ships and planes

verb: cut lumber, as in woods and forests