"The quality of our products has decreased since the main designer left."
2.VerbTo make (a quantity) smaller.
"Let's decrease the volume a little so we can hear each other talking."
3.NounAn amount by which a quantity decreases or is decreased.
"After six years of constant growth, the company reported a slight decrease in sales last year.; One research team has recorded Baishui’s decrease at about 27 meters per year over the last 10 years."
4.NounA reduction in the number of stitches, usually accomplished by suspending the stitch to be decreased from another existing stitch or by knitting it together with another stitch. See Decrease (knitting).