プログレッシブ和英中辞典(第３版)の解説
つみかさね【積み重ね】
〔蓄積〕accumulation; 〔積んで高くなった山〕a pile; a heap (▼pileは積み上げたもの，heapは雑然とした山)
- 経験の積み重ね
the accumulation of experience - それは彼の努力の積み重ねのお陰だ
It is due to his constant [unremitting] efforts. - この仕事は経験を積み重ねないとできない
You'll be able to do this work only after 「you accumulate [you've had] years of experience.