logloglogs1nouna thick round piece of wood from a tree: Put another log on the fire.logloglogsloggedlogging2verb (logs, logging, logged)to keep an official record of things that happensame meaningrecord: to log somebody's phone callslog in, log onto type your name, etc. so that you can start using a computer: You need a password to log on.log off, log outto stop using a computer: Make sure you log out before you switch off the computer.