noun-modifying (irregular)
internal combustion
Prenominal modifier used in technical terms such as 内燃機関 (internal combustion engine). Not used as a standalone noun.
内燃機関はガソリンや軽油を燃料とする。
Internal combustion engines use gasoline or diesel as fuel.
内燃機関と電動機を組み合わせたハイブリッド車が増えている。
Hybrid vehicles that combine an internal combustion engine and an electric motor are increasing.