If a word conforms to a special rule, I call it an Indivisible Word™.
Use the following examples below to find the rule.
Here is a CSV version:
Indivisible Word™,Not Indivisible Word™ ACE,PRO ICONS,SYMBOLS DRY,WET TENURE,FIRED VASE,PITCHER TAME,WILD ADORES,HATES DEBASE,REBASE BADGE,MEDAL LAD,GAL
These are not the only examples of Indivisible Word™ (or Not Indivisible Word™), more can be found.
Levieux has already pointed out atoms as "indivisible," but what are other things that might be described as indivisible? Concepts, words, numbers, nations, people?
A dozen, a gross, and a score
All times the third power of four
Take from that eleven
Times seventy seven
Then from that four-twenty-two more