Synonyms to grade by grade

by degrees, bit by bit, by inches, by inchmeal, by slow degrees, by snatches, degreewise, drop by drop, foot by foot, gradatim, gradually, in detail, in driblets, in installments, in lots, in small doses, in snatches, inch by inch, inchmeal, little by little, part by part, piece by piece, piecemeal, slowly, step by step, by snatc