noun
competitor's number bib; athlete's number
Refers to the cloth bib or the number itself worn by athletes in races or competitions. Derived from German 'Decke(n)'.
from German Decke(n)
マラソン選手はゼッケンを付けて走る。
Marathon runners run wearing a number bib.
彼のゼッケン番号は8番だった。
His competitor number was 8.