leaded petrol is a noun meaning "gasoline treated with a lead compound to reduce motor knocks". It carries one recorded sense.
gasoline treated with a lead compound to reduce motor knocks
“combustion of leaded gasoline released lead into the air where it could cause lead poisoning”
Definitions, synonyms and semantic relations for leaded petrol come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.