What does the term suspended jail term mean?

In my area it means you are sentenced BUT remain out of jail. If you do not offend again within a certain number of months (usually 6 or 12) the sentence is dropped and you serve no time.

It's similar to an adjournment in contemplation of dismissal - very similar.

Agree, that is what it is here also, you are sentenced to the time in jail, but they will allow you to stay out, but if you have any other issues, you will go straight to jail to serve that sentence. For the period they order.