Laconic is an adjective that describes a style of speaking or writing that uses only a few words, often to express complex thoughts and ideas. A more laconic way to write that last sentence might be this: laconic means brief.
There’s a friend of yours who doesn’t talk very much, and when he does, he says maybe three words and then becomes quiet again. You could describe that friend as laconic. The word comes from Laconia, a region in ancient Greece where the local Spartan rulers gave very short speeches. Being laconic can be bad when it sounds rude to be so brief, but it can be good if you’re in a rush to get somewhere.