noun, noun or participle which takes 'suru'
one row; one line; a single file
Refers to a single row or line of people or things. Often used with 並ぶ (to line up) or に並んで (in a row).
子どもたちが一列に並んで歩いている。
The children are walking in a single file.
机を一列に並べてください。
Please line up the desks in one row.