One has to be careful in identifying the nature of the word in a sentence where it could play a role of more than two. For example, Teena had to work late at night. Here, work represents a Verb whereas, in a sentence like Teena went to work, there the work represents a Noun.
In a sentence like ‘Sita sat second in the second row.’ The word second acts both as an adverb and an adjective in the given sentence, as the SECOND after sat describes the position of Sita making it an adverb, and the SECOND before row describes which row making it an adjective.