KanjiJLPT N1
Gradually

gradually, slowly, deliberately, gently

Mnemonic

The postman has an excess of heavy parcels—so many he can only move gradually. He inches along, the towering stack swaying with each careful step. The excess forces a slow, deliberate pace as he gradually delivers one package at a time down the endless street.
Additional thoughts
Visualize the postman buried under a comically huge pile of packages, forced into tiny shuffling steps. The sheer excess makes gradual movement his only option—rush and everything topples.
Quick recall
A postman buried in excess parcels can only deliver them gradually.

Details

The keyword for 徐 is gradually. This kanji conveys the sense of doing something slowly, gently, or at a leisurely pace. It implies a calm, unhurried progression rather than abrupt or sudden movement. The character is often associated with actions performed with deliberate slowness and composure.
On'yomi
じょ
Kun'yomi
おもむ.ろに

Used in vocab