B2 每天，天天;日益，越来越
every day, or more and more as each day passes
Day by day he became weaker. 他的身体日渐虚弱。
These birds are disappearing day by day as their habitat shrinks.
His anger grew day by day.
The demand for this product is increasing day by day.
The situation is grave and worsening day by day.
Day by day, his hopes grew stronger.
See also: day