COMMON If you have a list as long as your arm, you have a very long list. I've got a list of players as long as your arm but it's just a matter of whether they're available. Note: The word list can be replaced by other words that refer to things that can be written as a list. By his late 30s, he already had a rap sheet as long as your arm — 52 convictions and a total of 16 years behind bars.