Usage of the word parenthesis

Question

What does the word parenthesis mean? Does it mean as an aside or in passing. I looked at dictionary definition, but I could not understand its application in the context of the sentence below.

I note in parenthesis that if a high earning household vacates a property, it may not, as the Croydon MP expected, be available to someone in greater need, because it may be deemed to be of higher value and have to be sold on the open market, possibly in London to a foreign buyer.

This sentence appears in the following link:

Housing and Planning Bill - Report (3rd Day)

Answer 1

in parenthesis is a phrase of the word the parenthesis.

From Lexico:

in parenthesis - As a digression or afterthought.

Digression means something that is not particularly needed in the context-of-speech and can be remarked as a brief sideline or departure from the main subject. That means this sentence was not entirely needed here, but he said it nonetheless. And yes, it can be termed as aside/s (noun).

Answer 2

'In parenthesis' literally means 'in brackets', like (this). You place brackets round a phrase when it is intended as a comment 'by the way' and is not part of the main argument. Here, the writer just says that the note is 'in parenthesis' without actually putting it in brackets.