diàn​jiǎo​shí

means of advancement

垫脚石 (墊腳石) diàn​jiǎo​shí
means of advancement noun
a person or situation used as a tool to improve one's status or career
stepping stone noun
a physical stone placed to provide a dry or stable place to step on in muddy or wet terrain

Frequency

Movie subtitles
0.510 per million appears in 0% of films
Written text
0.285 per million

Sources

Definitions
CC-CEDICT