塔 is built from the 土, 艹 (grass (top)), and 合 components.
It belongs to a phonetic family with 答 and 搭 — they share the 合 component and the reading トウ.
A common word using 塔 is 塔 (とう), meaning “tower, pagoda”.
Kanji that look similar include 堅, 堕, 堤, and 堪.