What is it called when a single word is offset by commas?

I'm not sure if I can generalize this type of construct, but is there a grammar term for single words surrounded by commas? Consider the following examples:

1. Let's assume you are given a length of time, say, 10 minutes.
2. Tristan was, unsurprisingly, late to the meeting.
3. The plain-looking building was, well, plain.

Are these known as appositives?

Solution 1:

The NOAD reports that one of the meaning of parenthesis is "a word or phrase inserted as an explanation or afterthought into a passage which is grammatically complete without it, in writing usually marked off by brackets, dashes, or commas."

The same dictionary reports that the meaning of apposition (to which I am redirected when I look for the grammatical meaning of appositive) is "a relationship between two or more words or phrases in which the two units are grammatically parallel and have the same referent (e.g. my friend Sue; the first US president, George Washington)."

It seems the right term is parenthesis.

Solution 2:

It's called a parenthesis.

See the Wikipedia article about it.