Log1  —n. 1 unhewn piece of a felled tree; any large rough piece of wood, esp. Cut for firewood. 2 hist. Floating device for gauging a ship's speed. 3 record of events occurring during the voyage of a ship or aircraft. 4 any systematic record of deeds, experiences, etc. 5 = *logbook. —v. (-gg-) 1 a enter (a ship's speed, or other transport details) in a logbook. B enter (data etc.) In a regular record. 2 attain (a distance, speed, etc., thus recorded) (had logged over 600 miles). 3 cut into logs.  log in = log on. Log on (or off) open (or close) one's online access to a computer system. Sleep like a log sleep soundly. [origin unknown]