Definition
An initial, approximate adjustment of the trim controls to relieve most of the control pressure required to hold a desired pitch, roll, or yaw attitude, with fine adjustments to follow once the airplane is settled in the new condition.
Plain English
A first, quick trim setting that takes most of the pressure off the controls. You get it close, then fine-tune it after the airplane has settled down.
Context Anchor
Used during attitude flying when the pilot changes pitch, power, or airspeed and needs to reduce control pressure quickly before settling into the new condition.
Derivation
Rough' here means 'approximate' or 'not yet refined' — the same sense as a 'rough draft.' It signals that the trim setting is a first pass, intended to be polished afterward.
Why Pilots Care
Rough trim reduces control workload and prevents over-controlling while the pilot stabilizes the new attitude.
Intuition Check
Rough trim does not mean the trim system is rough, damaged, or unsafe. It means the trim setting is approximate rather than exact.
Example Sentence 1
After leveling off at cruise altitude, the pilot applied a rough trim to relieve the forward control pressure, then made a small final adjustment once the airspeed stabilized.
Example Sentence 2
The pilot used rough trim first, then made small wheel adjustments until the aircraft maintained altitude with no control input.