This is the 15975th most frequent Russian word.
прочно
"Прочно" means "firmly" or "solidly" in English.
In this sentence, 'прочно' describes how the house is built, indicating stability and durability.
Этот дом построен прочно.
This house is built sturdily.
Here, 'прочно' metaphorically represents the solidity of the friendship like a stable structure.
Их дружба держится прочно.
Their friendship holds strong.
In this context, 'прочно' specifies the way the rope is fastened, emphasizing tightness and security.