by degrees
In gradual steps; bit by bit.
Rare and irregular at first, they gradually become more numerous and more constant and by degrees supplant the majuscule forms, so that in the history of the Roman cursive there is no precise boundary between the majuscule and minuscule periods. Source: Internet
And when you are told, "Arise," then arise; Allah will raise those who have believed among you and those who were given knowledge, by degrees. Source: Internet
Persons, therefore, starting with this natural gift developed by degrees their special aptitudes, till their rude improvisations gave birth to Poetry." Source: Internet
The subsidies had been reduced by degrees, as Henry gained more control of the nation. Source: Internet