What does light yellow watery semen mean. is it by std? no drippings, no burning or painful sensation while urinating

Watery semen: Some men have abundant contribution to the ejaculate fluid from the prostate gland, which can dilute the ejaculate somewhat. Without discharge when not ejaculating, or pain/burning when urinating, there is probably nothing to worry about. Most ejaculates are light yellow. Take a specimen to your healthcare provider for a microscopic look at the fluid.