na-adjective
customary; conventional; traditional; usual
Describes something done according to established custom or practice, often in social or cultural contexts.
日本では、お辞儀は慣習的な挨拶の仕方だ。
In Japan, bowing is a customary way of greeting.
慣習的な方法に従って、式を執り行った。
We conducted the ceremony according to traditional methods.
伝統的 implies a longer historical tradition, whereas 慣習的 can refer to any accepted practice, even relatively recent ones.
From 慣習 (custom, convention) + 的 (-like, -ic).