This is the 12513th most frequent Russian word.
коленному
"Коленному" means "to the knee" or "knee-related" in English, depending on context.
"Коленному" is used here to describe squatting or bending the knees in a specific posture.
Я сел по коленному на мягкий диван.
I sat cross-legged on the soft sofa.
"Коленному" here indicates a relationship originating from infancy or early childhood.
Он был предан своему коленному другу и всегда поддерживал его.
He was loyal to his childhood friend and always supported him.
"Коленные" is used metaphorically here, referring to discussions held informally, emphasizing immediacy or involvement.