By successive stages (of increase or decrease); †by degrees. Now rare.

That which follows as a result of an event or course of action; an after-consequence. in sequel to, as a consequence of. †by sequels: by…

figurative. esp. in by degrees: by successive steps or stages, by little and little, gradually.

In a progressive manner; in the way of progression or progress; spec. by continuous advance; step by step, gradually; successively.

By degrees, gradually, step by step.