noun
slow starter
Refers to a person, machine, or system that takes time to get going or reach full performance. Often used in sports, business, or technical contexts.
彼はスロースターターだから、最初はあまり期待しないで。
He's a slow starter, so don't expect too much at first.
このエンジンはスロースターターで、温まるまで時間がかかる。
This engine is a slow starter and takes time to warm up.