The most common and most likely answer to this crossword clue is the 11 letter word MEN-AT-ARMS
I've seen this crossword clue in The Times
M
E
N
-
A
T
-
A
R
M
S
More clues leading to the result MEN-AT-ARMS
Buddy explains!
The straight part
We know that "lines we once made up" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lines we once made up = men-at-arms.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MEN-AT-ARMS mean?
MEN-AT-ARMS noun- A heavily-armed mounted member of medieval cavalry.