This is the 11069th most frequent Russian word.
глубоко
"Глубоко" means "deeply" in English.
In this sentence, 'глубоко' conveys a metaphorical depth to emphasize the thoughtful and profound consideration.
Он глубоко задумался о жизни.
He thought deeply about life.
Here, 'глубоко' describes a physical depth as a characteristic of the river, implying it has considerable depth.
Эта река глубока и опасна для плавания.
This river is deep and dangerous for swimming.
In this context, 'глубоко' describes the act of inhaling fully, emphasizing the extent of the action.