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: 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, 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. [Pinyin]

     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. [Pinyin]

        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–

(grade 3 “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 kˠɛi).

• IPA^(key): [ka̠i]

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}}.