This is the 13835th most frequent Russian word.
обеда
"Обеда" means "lunch" or "dinner" depending on context.
'Обеде' is used in the prepositional case, referring to being 'at lunch' as in 'на обеде'.
На обеде мы обсуждали планы на вечер.
At lunch, we discussed plans for the evening.
'Обеда' functions as the genitive case of the noun 'обед', used in the phrasal construction 'после обеда' meaning 'after lunch'.
После обеда мы пошли гулять.
After lunch, we went for a walk.
'Обеда' appears in the genitive case again alongside 'до' to indicate 'until lunch'.