Meaning of “line (sb/sth) up” - Learner’s Dictionary

line (sb/sth) up

phrasal verb with line us uk /laɪn/ verb [ T ]

to stand in a row, or to arrange people or things in a row:

Books were neatly lined up on the shelves.

(Definition of “line (sb/sth) up phrasal verb, verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)