Aaronites. Aaronites, in the Hebrew text simply Aaron, the name being used collectively.

The priestly descendants of Aaron (1 Chron 12:27; 27:17, A. V.).

[Davis]

Aaronites
âr´on-īts לאהרון (le-‘ahărōn, literally, “belonging to Aaron”): A word used in the King James Version, but not in the revised versions, to translate the proper name Aaron in two instances where it denotes a family and not merely a person (1Ch 12:27;27:17). It is equivalent to the phrases “sons of Aaron,” “house of Aaron,” frequently used in the Old Testament. According to the books of Josh and Chronicles the “sons of Aaron,” were distinguished from the other Levites from the time of Joshua (e.g.Jos 21:4, 10, 13; 1Ch 6:54).

[ISBE]

AARONITES
Descendants of Aaron the high priest, so called 1Ch 12:27;27:17. Thirteen cities were assigned to them, in Judah and Benjamin, Jos 21:13-19; 1Ch 6:57-60.

[Amtrac]

the descendants of Aaron, and therefore priests. Jehoiada, the father of Benaiah, led 3,700 Aaronites as “fighting men” to the support of David at Hebron (1 Chr. 12:27). Eleazar (Num. 3:32), and at a later period Zadok (1 Chr. 27:17), was their chief.

[Easton]