'Definite' means clearly stated or decided, very specific ,certain ,confirmed and also distinct. Definite article Definite time 'distinct' means recognizably different in nature from something else of a similar type . Distinguished ,special or featured. It could mean also strong and definite. A distinct smell of perfume. A distinct cultural group . So the two adjectives are intersecting partly in meaning to convey almost the same ,yet their uses are different and they have in general other distinct meanings.

It is very difficult to explain the meanings of adjectives in isolation. Please can you give us more context? If you could tell us what nouns you would like to apply these adjectives to - or give us the sentence you would like to use them in - then we would be in a better position to help you.