Thanks for everyone's thoughts...so a few more details: The cylindrical end is indeed threaded. The blade end is snapped off or cut through with force. The object measures maybe 1.5 x 4 cm. It is made of brass. I had thought about a lamp shade fastener given the threaded end, but I'm not sure how to explain the bladed end. Neither edge of the blade end is sharp so I don't think it was a cutting tool. I've searched images on the web high and low with various search terms and I am at a loss. Look forward to other's thoughts. Keep the ideas coming...
Because it was found in your 'yard' and the 'blade' is attached at an angle to the fitting,
it might be the end of a spring loaded diverter from a rain-bird type of sprinkler head.
Since it is made of brass, many sprinkler parts are made from brass to avoid corrosion.
Thanks for the great idea Got_4X4. Some sort of yard tool might be right but I'm not sure it's part of a water sprinkler. On closer inspection, I think the blade part is actually iron or steel. The cylindrical part is definitely brass though. I have posted this to the "What is it?" forum which I realize now might be more appropriate. Thanks for everyone's thoughts...the hunt continues...