(idiomatic) At some unspecified or unknown time; eventually or once; at some point.

What is the meaning of somewhere along the line?

phrase. If something happens somewhere along the line or down the line, it happens during the course of a situation or activity, often at a point that cannot be exactly identified. Somewhere along the line he picked up an engineering degree.

Is it along the line or along the lines?

Along the Lines Of Meaning

Definition: Similar to something else. The phrase along the lines of refers to something that is similar to or like something else. It is common to use this phrase when comparing or discussing two things.