Rehum

also called Harim, Nehum · A man, in the time of Exile and Return · named in 5 verses

the name means Merciful Easton's Bible Dictionary

Rehum (or Harim or Nehum) was one of the leaders who returned to Jerusalem with Zerubbabel after the Babylonian exile.

From Easton's Bible Dictionary

Merciful. (1.) One of "the children of the province" who returned from the Captivity (Ezra 2:2); the same as "Nehum" (Neh. 7:7).

Easton's Illustrated Bible Dictionary, 1897 — public domain, quoted in full and unedited.

First named at Ezra 2:2.

Ezra 2:2 accompanied by Zerubbabel, Jeshua, Nehemiah, Seraiah, Reelaiah, Mordecai, Bilshan, Mispar, Bigvai, Rehum, and Baanah. This is the count of the men of Israel:
Nehemiah 7:7 accompanied by Zerubbabel, Jeshua, Nehemiah, Azariah, Raamiah, Nahamani, Mordecai, Bilshan, Mispereth, Bigvai, Nehum, and Baanah. This is the count of the men of Israel:
Nehemiah 10:5 Harim, Meremoth, Obadiah,
Nehemiah 12:3 Shecaniah, Rehum, Meremoth,
Nehemiah 12:15 of Harim, Adna; of Meraioth, Helkai;