For Amazon, the custom field name should be "Condition" or "Amazon Item Condition". It should be created as a Lightspeed drop-down menu with choices.
Condition notes should be a custom field called "Condition Notes" or "Amazon Item Condition Notes"
Below you will find a default list of values accepted by Amazon for most products:
New
UsedLikeNew
UsedVeryGood
UsedGood
UsedAcceptable
CollectibleLikeNew
CollectibleVeryGood
CollectibleGood
CollectibleAcceptable
Refurbished
Your drop-down choices in Lightspeed should perfectly match the spelling, spacing and capitalization accepted by Amazon.