Express the superlative degree; 'the most', 'the best', 'the least'.
Long explanation:
The A が いちばん~ grammar point is used to express a superlative degree or the highest rank. It can be translated as 'the most', 'the best', or 'the least' in English. The formation is used with various adjectives and verbs, and can also be used in comparison with other items or people.