What do you call the 2 line of poetry?

There isn't one specific name for a two-line unit of poetry. However, depending on the context, you might call it:

* A couplet: This is the most common term for two lines of poetry that rhyme and often form a complete thought.

* Two lines: This is a simple and straightforward description.

* A distich: This is a more formal term that emphasizes the fact that it's a two-line unit within a larger poem.

* A verse: While "verse" typically refers to a single line, it can also be used for a two-line unit in some cases.

The best term to use depends on the specific situation and what you want to emphasize.