altitude vs attitude

The core difference

• altitude — height above a reference level, usually sea level. At an altitude of 10,000 metres, altitude sickness, high-altitude training.
• attitude — a way of thinking or feeling; a manner; a posture. A relaxed attitude to deadlines, she has attitude, the aircraft's attitude (its angle relative to the horizon).

The tell

Altitude carries alt, "high" — as in alto and exalt. Attitude carries apt in disguise — it is the same word as aptitude, a fitness or disposition, which became a posture and then a frame of mind. Height on one side, stance on the other.

In use

• altitude — The plane levelled off at cruising altitude. Altitude sickness sets in above 2,500 metres.
• attitude — His attitude to the job changed overnight. The glider was in a nose-down attitude.

Common slips

• flying at a high attitude → flying at a high altitude
• he has an altitude problem → he has an attitude problem

Alt is high; attitude is how you stand.

Where the words come from

Altitude is from Latin altitudo, "height", from altus "high". Attitude came through French from Italian attitudine, "disposition, posture", from Late Latin aptitudo — the same source as aptitude. It was first an artists' term for the pose of a figure; the frame-of-mind sense is nineteenth century.