ルイ, ライ, スイ, とりで
fort, rampart, walls, base(ball)
JLPT0 G13 S0 F5000
畾# is 田 field (tripled). This element is a variant of one that added another 夕 element at the bottom left of 多 (tall, neat pile of meat). 壘 is 畾 (pile) + 土 earth → earth piled into a long/tall and winding *rampart* → (baseball) *base*.
[Full Kanji Etymology List]