leak-proof From WikiWord, the free dictionary English Contents DefinitionsRelated wordsReferences DefinitionsadjectiveResistant to leaks; hermetic, sound; as of a dry cell battery. Related wordsSynonymswaterproofairtightwatertightleakproofsealedtightimperviousgas-tightwater-proofair-tightfire-proofacid-proofodourproofrot-proofair tightsoot-proof References Wiktionary — leak-proof Wikipedia — leak-proof