I came across the word “off-the-shelf” in the following sentence of Time magazine’s article “The 50 Best Inventions of the Years (Nov.11 issue).
He (inventor of the first synthetic cell) started with ‘off-the-shelf chemical’, and managed to reconstruct the genome of bacterium that successfully ‘booted up.’
I checked out the word “off-the-shelf” with a dictionary at hand, which defines it as “in stock, ready-made, easily available.”
Although this may be a naive question to most of native English speakers, it casted me a question, why does “off-the-shelf” which sounds to me “off the store-shelves” akin to “out-of-stock” on its face come to mean ready made and easily available? Can somebody explain it to me?