hunt, autumn hunting, to capture with a fine net
獮 centers on hunting, specifically the organized autumn hunt, and the method of capturing game with a fine net.
獮 combines 犭 (animal) with 爾, which likely contributes the sound and may relate to the idea of spreading a net. The exact historical development is uncertain.
The animal radical 犭 beside 爾, which resembles a net spread out, suggests hunting animals with a fine net during autumn.
For セン, imagine a hunter sending a fine net over the animals: send -> セン, and the net captures them.