Noun:
1: log a segment of the trunk of a tree when stripped of branches
2: log, backlog large log at the back of a hearth fire
3: log, logarithm the exponent required to produce a given number
4: log a written record of messages sent or received; "they kept a log of all transmission by the radio station"; "an email log"
5: log a written record of events on a voyage (of a ship or plane)
6: log 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
Verb:
1: log enter into a log, as on ships and planes
2: lumber, log cut lumber, as in woods and forests