An அடி type: a line built from exactly 4 சீர் - also called நேரடி, the most common line length in classical verse.

When someone imagines a typical Tamil verse line in their head, it's almost always an அளவு அடி - 4 சீர் is the workhorse length of classical poetry.

The standard 4-foot line most ஆசிரியப்பா and கலிப்பா verses are built from.