于 is a pictographic character. In oracle bone, the character depicts the airflow passing obstacles. For its original meaning, there are also other different versions. 于 serves as a phonetic component to form characters.
Extended meanings in modern Chinese
1.in; at; on; by; from,
2.than; then; to; with reference to
3.compared with
4.a Chinese family name
Characters formed by the phonetic component 于
竽, 圩, 纡, 玗, 盂, 芋, 釪 with the same pronunciation yú
杅, 穻, 迂, 弙, 趶, 扜 with the same pronunciation yū
吁, 訏, 旴, 盱 with the same pronunciation xū
宇 yǔ
邘 wéi