This is the 12986th most frequent Russian word.
ложь
Lie; falsehood.
In this sentence, 'ложь' is used as a noun to describe a false statement or untruth.
Я узнал, что это была ложь.
I found out that it was a lie.
Here 'ложь' conveys the idea of a statement that is intentionally untrue, emphasizing its deceptive nature.
Его слова звучали как полная ложь.
His words sounded like complete falsehood.
In this example, 'лжи' (a variation of 'ложь' in the genitive plural case) is used to describe the abstract concept of deception.