Russian
Noun
пуп • (pup) m inan (genitive пупа́, nominative plural пупы́, genitive plural пупо́в)
-  (anatomy) belly button, navel, umbilicus
-  глуп как пуп! ― glup kak pup! ― silly (humorous)
 
-  пуп земли ― pup zemli ― hub of the universe
 
 
Declension
Declension of пуп (inan masc-form hard-stem accent-b) 
 
 
Synonyms
References
-  Fasmer, Maks (1964–1973), “пуп”, in Etimologičeskij slovarʹ russkovo jazyka [Etymological Dictionary of the Russian Language] (in Russian), translated from German and supplemented by Trubačev O. N., Moscow: Progress
 
 
Serbo-Croatian
Etymology
From Proto-Slavic *pǫpъ (Russian пуп (pup), Polish pęp).
Pronunciation
Noun
пу̏п m (Latin spelling pȕp)
-  bud, burgeon
 
Declension
Declension of пуп
|   | 
 singular | 
 plural | 
|  nominative
 | 
 пу̏п
 | 
 пу̀пови
 | 
|  genitive
 | 
 пупа
 | 
 пупова
 | 
|  dative
 | 
 пупу
 | 
 пуповима
 | 
|  accusative
 | 
 пуп
 | 
 пупове
 | 
|  vocative
 | 
 пупе
 | 
 пупови
 | 
|  locative
 | 
 пупу
 | 
 пуповима
 | 
|  instrumental
 | 
 пупом
 | 
 пуповима
 | 
 
 
References
-  “пуп” in Hrvatski jezični portal