入れる
いれる · ireru · JLPT N5 · verb-ichidan
to put in
📥 入 = enter + れる: make it enter, so put in (i-reru)
The kanji 入 means enter. 入る (hairu) is to go in by yourself; 入れる (ireru) is the transitive partner: you cause something to go in. Same kanji as 入口 (iriguchi), the entrance.
入 — single pictograph, two slanting strokes
入 is a pictograph showing an arrowhead or pointed entrance, with two strokes converging downward to suggest something going inward. The original sense was 'to enter,' and it still carries that meaning today. It contrasts visually with 人 (person), where the strokes cross differently at the top.