斉
セイ, サイ, そろ.う, ひと.しい, ひと.しく, あたる, はやい, ただ, なり, ひと, ひとし
adjusted, alike, equal, similar variety of
JLPT1 G7 S8 F1209
The relevant oracle bone form of 齊 shows three slender, diamond-shaped objects arranged/aligned neatly. A bronzeware inscription form adds 二# (align), while a seal inscription form transforms 二 into a board (or a piece of cloth; in either case acting to represent things in general; compare 牛 in 物, and 半) → *equality*; *arrange*; *neater*; *all together* (← match up/align).
[Full Kanji Etymology List]