An onomatopoeia for a loud cracking or snapping sound (e.g., branches breaking, knuckles cracking). Also used to describe very tense or stiff muscles/body.
朝、体をひねると背中がバキバキと音がした。
In the morning, when I twisted my body, my back made a cracking sound.
運動不足で筋肉がバキバキに張っているので、ストレッチをした。
My muscles were very tight from lack of exercise, so I did some stretches.
風で枝がバキバキ折れて庭に散らばった。
Branches cracked and broke in the wind and scattered across the garden.