Yup, it’s just like if you have two kids on the same street with the same name. We had “Big Matt” and “Little Matt;” and the apostles had “Big Jim” and “Little Jim.”
In old fashioned English, which is used in most English translations of the Bible, The term less or lesser when referring to people means young or younger.
St. James, to distinguish him from the other apostle James, was called the Less.
The appellation may have taken its rise from his having been called later to the apostleship than the brothers James and John.
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.