뿌리를 내리다 (the dictionary form) literally translates to "to put down roots," like a tree anchoring itself into the earth. It's a beautiful metaphor for finding stability and establishing oneself.
In the song, Seungmin uses this phrase to express the idea of enduring through hardships, singing about it right after the line 눈이 내리고, 바람이 세서 (when the snow falls and the wind is strong). It’s a powerful and poetic image of resilience, symbolizing the strength to grow and persevere no matter the storm.
Have you ever felt like you were trying your hardest but still falling behind? Seungmin opens this song by admitting just that: he was running forward, trying to do well, but he tripped and got left behind. Right at the moment he thinks, "왜 하필 나만 이래" (Why is it only me like this?), he looks over and sees someone else crying beside him. This song isn't about being strong alone; it's about finding strength when you realize you're not the only one struggling.
From that point on, the song becomes a promise. It's a promise to stick together, even if they're a little slow or lost in the dark. Seungmin uses the beautiful image of a tree in winter to describe this promise: even when the snow falls and the wind is strong, they will "뿌릴 내리고, 가지를 뻗고" (put down roots and stretch out branches), waiting together for a better day. The goal is to one day look at each other with the "세상 가장 푸르른" (greenest in the world) smiles, knowing they made it because they had each other.