spring ‧ board /ˈsprɪŋbɔːd $ -bɔːrd/ BrE AmE noun [countable]
1 . something that helps you to start doing something
springboard for
The TV soap has been a springboard for a lot of careers.
2 . a strong board for jumping on or off, used when diving (↑ dive 1 (1)) or doing ↑ gymnastics