This is the 13879th most frequent Russian word.
обмазал
"Обмазал" means "smeared" or "coated" in English.
The word 'обмазал' is used to describe the act of applying a thin layer of a substance (butter) onto a surface (bread).
Он обмазал хлеб маслом.
He spread butter on the bread.
Here, 'обмазал' is used to depict a possibly excessive or careless action of spreading paint on a large area (walls).
Ребёнок обмазал стены краской.
The child smeared paint on the walls.
In this sentence, 'обмазал' refers to a systematic and purposeful application of protective substance on an object (roof).