noun, noun or participle which takes 'suru'
exchange; replacement; substitution
Rare noun/suru-verb meaning to exchange or replace something. In modern Japanese, 交代 or 交替 are overwhelmingly more common for this meaning.
古い文献では、役人の更代について記されている。
In old documents, the replacement of officials is recorded.
部品の更代が必要だ。
The part needs to be replaced.