What is the meaning of ?

The hiragana syllable (da). Its equivalent in katakana is (da).

Following parts of speech that do not inflect by themselves, including nouns, na-adjectives, adverbs and postpositional phrases.

  1. to be

    to be

    should; be obliged to; ought to

    Some forms also follow inflectable words.

    1. です follows i-adjectives, as the standard polite terminal form for i-adjectives.

      です follows i-adjectives, as the standard polite terminal form for i-adjectives.

      だろう / でしょう / なら can follow any inflectable word, forming suppletive volitional/polite volitional/conditional forms.

      Not following any words, but used before some conjunctives or in some inflected forms, to represent the aforementioned statement.

      who

      Source: wiktionary.org