There is a lot of overlap within all the adjectives mentioned. The following definitions and examples are from my own personal observation.
“Used” indicates the item has been owned before. A new car becomes used the second the first owner drives it off the lot.
“Reconditioned” indicates that the item has been repaired, or has had parts replaced in order to extend the life of the item in its original form. Sometimes these types of items are sold with a limited warranty.
“Deconstructed” is usually used for items that were a part of a larger object and can now be used individually. An example would be items salvaged from a demolition of a building, such as bricks, tiles, wrought iron features, doors, windows, etc. This also applies to clothing, including such items as embroidered appliqués salvaged from old clothing.
“Repurposed” refers to any item used for something other than its original “purpose” or design. Many deconstructed items are repurposed.
“Reconstructed” again can refer to anything from construction projects to clothing and more. In the construction industry, it usually refers to a structure that has been “deconstructed”, that is, taken apart piece by piece, and constructed again, usually in another location. Barnwood Builders, if you aren’t familiar with it, is about a construction crew that specializes in deconstruction and reconstruction and/or repurposing of old buildings.
“Recycling” usually refers to the processing of discarded items so that the materials used in the creation of those items can be reused to create other items, such as recycled plastic, metal or paper. Broadly, the term can be used for all of the above
In your example of the cut-off jeans, the shorts would be used, where the items made by the legs would be reconstructed of repurposed denim. All of these are types of recycling.