Perhaps from Proto-Semitic *rukba- (“knee”), metathetic form of Proto-Semitic *birk- (“knee”), whence also the root ب ر ك (b-r-k). Ehret (1995) derives this word from Proto-Afroasiatic *ruk- (“to bend”) instead.
رُكْبَة • (rukba) f (dual رُكْبَتَانِ (rukbatāni), plural رُكَب (rukab) or رُكْبَات (rukbāt))
| Singular | singular triptote in ـَة (-a) | ||
|---|---|---|---|
| Indefinite | Definite | Construct | |
| Informal | رُكْبَة rukba |
الرُّكْبَة ar-rukba |
رُكْبَة rukbat |
| Nominative | رُكْبَةٌ rukbatun |
الرُّكْبَةُ ar-rukbatu |
رُكْبَةُ rukbatu |
| Accusative | رُكْبَةً rukbatan |
الرُّكْبَةَ ar-rukbata |
رُكْبَةَ rukbata |
| Genitive | رُكْبَةٍ rukbatin |
الرُّكْبَةِ ar-rukbati |
رُكْبَةِ rukbati |
| Dual | Indefinite | Definite | Construct |
| Informal | رُكْبَتَيْن rukbatayn |
الرُّكْبَتَيْن ar-rukbatayn |
رُكْبَتَيْ rukbatay |
| Nominative | رُكْبَتَانِ rukbatāni |
الرُّكْبَتَانِ ar-rukbatāni |
رُكْبَتَا rukbatā |
| Accusative | رُكْبَتَيْنِ rukbatayni |
الرُّكْبَتَيْنِ ar-rukbatayni |
رُكْبَتَيْ rukbatay |
| Genitive | رُكْبَتَيْنِ rukbatayni |
الرُّكْبَتَيْنِ ar-rukbatayni |
رُكْبَتَيْ rukbatay |
| Plural | basic broken plural triptote; sound feminine plural | ||
| Indefinite | Definite | Construct | |
| Informal | رُكَب; رُكْبَات rukab; rukbāt |
الرُّكَب; الرُّكْبَات ar-rukab; ar-rukbāt |
رُكَب; رُكْبَات rukab; rukbāt |
| Nominative | رُكَبٌ; رُكْبَاتٌ rukabun; rukbātun |
الرُّكَبُ; الرُّكْبَاتُ ar-rukabu; ar-rukbātu |
رُكَبُ; رُكْبَاتُ rukabu; rukbātu |
| Accusative | رُكَبًا; رُكْبَاتٍ rukaban; rukbātin |
الرُّكَبَ; الرُّكْبَاتِ ar-rukaba; ar-rukbāti |
رُكَبَ; رُكْبَاتِ rukaba; rukbāti |
| Genitive | رُكَبٍ; رُكْبَاتٍ rukabin; rukbātin |
الرُّكَبِ; الرُّكْبَاتِ ar-rukabi; ar-rukbāti |
رُكَبِ; رُكْبَاتِ rukabi; rukbāti |
رَكَبَة • (rakaba) m pl
| Root |
|---|
| ب ر ك |
| 1 term |
ركبة • (rukba) f (dual ركبتين (rkubtayn), plural ركاب (rkāb) or ركبات (rukbāt) or ركابي (rkābi))
| Root |
|---|
| ر ك ب |
| 3 terms |
ركبة • (rukbe) f (plural ركب (rukab) or ركاب (rkāb))