Word Knowledge Question on the Suffix -Less

In my role as an ASVAB tutor, I remind my students that reviewing prefixes, root words, and suffixes is a useful method to expand their vocabulary.  The purpose of expanding their vocabulary is to improve their scores on the Word Knowles section of the ASVAB. Today I present a question:

What does the suffix -less mean?

There are many English words with the suffix -less.  Some examples are heedless, listless, reckless, fruitless, hapless, and relentless.

Do you know what -less means?  I will present the answer and explanation tomorrow.