ボウ, それがし, なにがし
so-and-so, one, a certain, that person
JLPT1 G7 S9 F2106
木# tree/wood + 甘 (sweet food contained in the mouth) → plum (i.e., a dark fruit that grows in abundance, and is consumed by being savored in the mouth). Compare 梅. *A certain* and *some* are borrowed meanings.
[Full Kanji Etymology List]