SLOWLY &c. adj.; leisurely; piano [It.], adagio [It.], largo [It.], larghetto [It.], at half speed, under easy sail; at a -foots, - snails, - funeral- pace; dead slow [colloq.]; slower than- death, - cold molasses [colloq.], - a funeral; in slow time; with mincing steps, with clipped wings; haud passibus quis [Vergil]; in low (gear or speed) [automobiling].
GRADUALLY &c. adj.; gradatim; by degrees, by slow degrees, by inches, by little and little; step by step; inch by inch, bit by bit, little by little, seriatim [L.], consecutively.
Dum Roma deliberat Saguntum perit.
That, like a wounded snake, drags its slow length along.Pope