What is -st dec- short for in a crochet pattern?

Question

*work 3 st dec in next 3 ch, dc in next 6 ch, 3 dc in next ch, dc in next 6 ch; Repeat from * across. End by working 2 st dec in last 2 ch.

I understand everything but st dec.

Answer 1

It is stitch decrease. If there are no instructions, you can do this by making it tighter or anyway you can think of to make it become smaller. Baisically it means to decrease the guage you had before.

Answer 2

It means than in the next three ch you will yo and pull up a loop without finishing each stitch individually, then yo and pull through all loops on the hook, making a decrease of 3 stitches into 1 stitch.

Answer 3

"st dec" is stitch decrease  there should be a special note somewhere telling you how to do this particular st dec

a lot of times I work half of  a double crochet then start another one and work half of it then yarn over and go through all the loops on the hook. This makes a good stitch decrease without leaving holes where you don't want them.

A 3 st dec would be working half of each of 3 chains then doing the yarn over and through all loops on the hook. The one above would be a 2 st dc.

Am I making sense this morning?