What does laconic mean?

Laconic is an adjective that means brief or terse in speech or expression — that is, using few words. You might be more familiar with its synonym, concise.

Here's an example of its usage from Bleak House, by Charles Dickens:

First, Jo has to complete his errand of good nature by handing over the [medicine] he has been to get, which he delivers with the laconic verbal direction that "it's to be all took d'rectly."