Semantic. 耳(ear) and 又(hand). To take an enemy's ear and carry it in your hand.
This entry lacks etymological information. If you are familiar with the origin of this term, please add it to the page per etymology instructions. You can also discuss it at the Etymology scriptorium. Particularly: “How did this glyph come about? Neither 耳 or 又 are phonetic components and at least don't seem to be semantic components.”