Question

he did not speak_ word in self defence fill
article here

Answer 1

he did not speak 'a' word in self defence

Answer 2

There are three types of articles definite, indefinite and zero articles.

The definite article is the, that appears before the specific noun, Indefinite articles are – a & an, they appear before unspecific nouns.

When no articles appear before the noun are called zero article  

Answer:  He did not speak a word in self defence.