Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
Further, each Skill Division below Iridescent has its three tiers to progress through before reaching the next Skill Division.
Source: https://gamerant.com/call-of-duty-modern-warfare-2-ranked-play-tiers-explained/