ponderously

adverb
1
in a way that is too slow and careful; in a serious and boring way
کندانه, سنگین وار, کند و سنگین, به طور ملال‌آور
synonym tediously
2
slowly and heavily
به‌آهستگی, به‌سنگینی, سنگین‌وار
Slowly, ponderously, we climbed the steep stone roadway.