赫

A compound ideograph composed of:

赤 + 赤 — two instances of the character for “red.” The duplication emphasizes intense redness or brilliance, giving the meaning bright, blazing, or radiant.
Semantic development: - bright red color; - shining or blazing; - brilliant or illustrious (figurative).

혁혁 (赫赫) — brilliant; illustrious; splendid

혁혁한 공로 — outstanding achievements

Outside this expression, the character is rarely used in ordinary vocabulary and appears mainly in personal names.

In Korean, 赫 is frequently used in personal names, often read 혁 (Hyeok).

Aside from the word 혁혁 (赫赫), it rarely appears in everyday vocabulary.

Some Korean clans use 赫 as a generational name character (항렬자). For example, the Andong Kwon clan (안동 권씨) uses it for the 36th generation.