Word: knockproof
Part of speech: Adjective
Syllables: knock
proof
Definition: Preventing or reducing the occurrence of engine knock.
Morphemes:
Affix: knock
Language: en
PoS: Verb
Meaning: To bump or impact.
Affix: -proof
Language: en
PoS: Suffix
Meaning: Used to form adjectives denoting an impervious or impenetrable quality.