I thought of this one yesterday, as I was at my part-time job and we were discussing the disappointment involved when you get a new piece of office equipment and it doesn’t quite come up to expectations (I’ll miss that office … ). Were we dissatisfied or unsatisfied? Well, in this case, probably both, but there is a difference!
To dissatisfy (yes, that’s a word!) is to fail to satisfy, and if you’re dissatisfied then you are not content or happy; you are experiencing a lack of satisfaction. “I was dissatisfied with England’s performance in the test match”.
The dictionary helpfully defines unsatisfied as not satisfied, but the definition for unsatisfactory does get across the sense of “not good enough”. So if there’s not enough of something, or it is lacking in itself, then you’re unsatisfied (if it’s perfectly good for purpose, but not liked by you, then I’d say that you’re dissatisfied). “The portion of cake was so small that she was left unsatisfied and wanting more”.
“I hate this printer. I don’t know if I’m dissatisfied because it isn’t what I expected from an office printer, or unsatisfied because it never finishes a print job.”