There may be a more recent definition (16C/34C at SEA is ‘relatively’ recent), but that does not change the original designation of FOD.
From a Lockheed-Martin Training slideshow titled “Foreign Object Damage Prevention”:
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Formal Definition:
Foreign Object Damage (FOD) - Any damage attributed to a foreign object that can be expressed in physical or economic terms which may or may not degrade the product’s safety and / or performance characteristics.
Foreign Object Debris (FOD) - A substance, debris, loose hardware, or article alien to a vehicle or system which could potentially cause damage.
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I was outside on the tarmac at SeaTac on projects in 93-96 where the FOD regarded debris (we had to be really careful not to drop anything, etc.). I imagine guys repairing the planes would use the term “damage” more often.
Interesting that they have the same acronym for two related, but related things.