A Laconicism, Laconism

1. (uncountable, rhetoric) Extreme brevity in expression. Synonyms: conciseness, laconicism, succinctness
2. (countable) A very or notably brief expression. Synonyms: brevity, epigram

Synonyms

(extreme brevity in expression): conciseness, laconicalness, succinctness

(a very or notably brief expression): brevity, epigram