This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. comparative form of heavy: more heavy

"That's true of both die-hard Democrats and Republicans who turn out in heavier numbers than unaffiliated voters in midterms and others who may be well-versed in the big races but know little about other contests."

heavier-than-air