bogging is exactly what the word sounds like.
when your engine "bogs" it loses power and is sluggish, won't rev up. just like when you get bogged down when you're tired..no energy to do anything.
usually bogging is caused by an air-fuel mixture that is too lean and the bog will occure at wide open throttle / higher rpms. a bog can also be caused by too rich of an air-fuel mixture, and normally that will happen at lower rpms. the engine will not seem to have much power and it will take a while for it to build rpms.