(1):

(a.) Expressing much in few words, after the manner of the Laconians or Spartans; brief and pithy; brusque; epigrammatic. In this sense laconic is the usual form.

(2):

(a.) See Laconic, a.

(3):

(a.) Laconian; characteristic of, or like, the Spartans; hence, stern or severe; cruel; unflinching.