This is the 1806th most frequent Russian word.
легких
The Russian word "лёгких" means "lungs" (genitive plural form).
Here, 'лёгких' refers to the quality of the movements being effortless and graceful.
У неё лёгких движений кистью, словно она художник.
She has smooth movements with her brush, as if she were an artist.
In this sentence, 'лёгких' describes the mistakes as being simple or trivial.
Игроки избегают лёгких ошибок, чтобы не терять очки.
Players avoid minor mistakes to prevent losing points.
Here, 'лёгких' refers to the anatomical term 'lungs' in Russian.