This is the 14142nd most frequent Russian word.
опозданий
The word "опозданий" in Russian means "of delays" or "of tardiness."
Here, "опозданий" is used in the genitive plural to quantify the occurrences of being late.
Он попросил простить его за множество опозданий.
He asked to be forgiven for numerous delays.
"Опозданиям" is in the dative plural form, showing the grammatical relationship as an indirect object in the sentence.
Учитель терпеливо относится к опозданиям учеников.
The teacher is patient with students' tardiness.
In this sentence, "опозданий" is in the genitive plural form, referring to multiple instances of lateness or delays.