foothold

noun
1
a place where your foot can be safely supported when climbing
جای پا, محل پا گذاشتن, تکیه‌گاه پا
2
a strong position in a business, profession, etc. from which somebody can make progress and achieve success
جای پا, موضع مستحکم, پایه موفقیت
The company is eager to gain a foothold in Europe.
With this upcoming deal we hope to establish a permanent foothold in the US market.
I hope the book will provide a foothold for students of the subject.