階

階 (Kangxi radical 170, 阜+9, 12 strokes, cangjie input 弓中心心日 (NLPPA), four-corner 7126₁, composition ⿰阝皆)

• 𣾂

• Kangxi Dictionary: page 1357, character 9
• Dai Kanwa Jiten: character 41755
• Dae Jaweon: page 1861, character 9
• Hanyu Da Zidian (first edition): volume 6, page 4143, character 4
• Unihan data for U+968E

Historical forms of the character 階
Shuowen Jiezi (compiled in Han)	Liushutong (compiled in Ming)
Small seal script	Transcribed ancient scripts

Phono-semantic compound (形聲 / 形声, OC *kriːl): semantic 阝 + phonetic 皆 (OC *kriːl).

階

1. stair; step

   階梯／阶梯  ―  jiētī  ―  staircase

   • 夫不違，乃違也。夫不違，亡之階也。 [Classical Chinese, trad.]
     夫不违，乃违也。夫不违，亡之阶也。 [Classical Chinese, simp.]

     From: Guoyu, circa 4^th century BCE

     Fú bùwéi, nǎi wéi yě. Fú bùwéi, wáng zhī jiē yě.

     They never go against you, which is indeed their way of betraying you. Their unconditional compliance is the stepstone to you ruin.

2. (figurative) rank; degree; level; seniority; order of precedence

   官階／官阶  ―  guānjiē  ―  rank of an official

   進階中文課／进阶中文课  ―  jìnjiē zhōngwén kè  ―  advanced(-level) course in Chinese

3. (figurative) phase; stage (serially-ordered division of time, level of completion, etc.)

   階段／阶段  ―  jiēduàn  ―  stage

4. (music) scale

   五聲音階／五声音阶  ―  wǔshēngyīnjiē  ―  pentatonic scale

5. (mathematics) order; degree (quantity signifying various concepts in mathematics, chiefly integer-valued)

   二階微分方程／二阶微分方程  ―  èrjiē wēifēnfāngchéng  ―  second-order differential equation

   1. (graph theory) the number of vertices in a graph

      • 顯然任何n階圖是一個n部圖。 [MSC, trad.]
        显然任何n阶图是一个n部图。 [MSC, simp.]

        From: 2012, Xiong Bin and Zheng Zhongyi, Graph Theory, page 18

        Xiǎnrán rènhé n jiē tú shì yīge n bù tú.

        Evidently, every n-vertex graph is an n-partite graph.

6. a surname

• “階”, in 漢語多功能字庫 (Multi-function Chinese Character Database)‎, 香港中文大學 (the Chinese University of Hong Kong), 2014–

(Third grade kyōiku kanji)

1. storey; story; floor​

• Go-on: け (ke)
• Kan-on: かい (kai, Jōyō)
• Kun: きざはし (kizahashi, 階)、はしご (hashigo, 階)、しな (shina, 階)

From Middle Chinese 階 (MC keaj).

• (Tokyo) かい (Heiban – )
• IPA^(key):

階(かい) • (kai) 

1. step; stair; storey
2. class; rank; level

階(かい) • (-kai) 

1. floors, storeys (of a building)

   （私(わたし)の）オフィスは五(ご)階(かい)にあります。

   (Watashi no) ofisu wa go-kai ni arimasu.

   (My) office is on the fifth floor.

階 (eumhun 섬돌 계 (seomdol gye))

1. hanja form^? of 계 (“steps, stairs”)
2. hanja form^? of 계 (“rank, degree”)

階: Hán Nôm readings: giai

1. This term needs a translation to English. Please help out and add a translation, then remove the text {{rfdef}}.