This is the 8993rd most frequent Russian word.
ребенка
The word "ребёнка" is the genitive or accusative singular form of "ребёнок," which means "child" in English.
Used in singular genitive case to indicate 'for the child'.
Я нашел игрушку для ребенка.
I found a toy for the child.
Used in singular accusative case to indicate 'about the child'.
Она заботится о ребенка весь день.
She takes care of the child all day.
Used in singular genitive case to indicate possession.