a piece of written criticism

[GoldfishLord]

critique:
a piece of written criticism of a set of ideas, a work of art, etc.

Source: critique noun - Definition, pictures, pronunciation and usage notes | Oxford Advanced Learner's Dictionary at OxfordLearnersDictionaries.com

Does "a piece" mean "a single item of a particular type"? If not, what does it mean?

 

[5jj]

That dictionary gives the following as definitions of 'piece':

4,
[countable] piece (of something)(used especially with uncountable nouns)a single item of a particular type, especially one that forms part of a set

• a piece of equipment/furniture
• a piece of clothing/luggage
• a piece of machinery
• a 28-piece dinner service

5. [countable] piece of something used with many uncountable nouns to describe a single example or an amount of something

• a piece of information/evidence/advice/news/legislation
• a piece of software
• This is a superb piece of work.
• It was an interesting piece of research.
• The building is a piece of history (= of historical interest or importance).
• Isn't that a piece of luck?
• You should eat at least two pieces of fruit a day.

6. [countable] a single item of writing, art, music, etc. that somebody has produced or created; a short item of writing from a longer work

• piece of something a piece of music/art
• a fine piece of writing
• They performed pieces by Bach and Handel.
• The painting is a companion piece to (= is closely related to and intended to be displayed with) an earlier work.
• (formal) They have some beautiful pieces (= works of art, etc.) in their home.
• piece from something She read a piece from ‘Alice in Wonderland’.
• Homophones peace | piece

7.[countable] an article in a newspaper or magazine or a broadcast on television or radio

• The Washington Post ran a series of opinion pieces criticizing the policy.
• piece about/on something Did you see her piece about the internet in the paper today?

 

[GoldfishLord]

Does the use of it match sense 5?

 

[5jj]

#5, #6 and #7 all give a pretty good idea of the meaning of 'piece' in 'piece of written criticism'.