adverb

in a gradual way; slowly; by degrees.

the situation gradually improved

slowly,moderately,unhurriedly,cautiously,gently,gingerly,circumspectly,unspectacularly,piecemeal,step by step,little by little,bit by bit,inch by inch,piece by piece,drop by drop,by degrees,progressively,successively,continuously,systematically,slowly but surely,regularly,steadily,evenly,constantly,consistently,uniformly,at a regular pace,inchmeal,gradatim