This is the 549th most frequent Russian word.
чуть
Slightly; a bit; barely.
Here, 'чуть' means 'almost' and is used to describe a near event that did not occur.
Я чуть опоздал на поезд.
I almost missed the train.
In this sentence, 'чуть-чуть' is a reduplication meaning 'a little bit' or 'slightly', stressing minimal amount.
Чуть-чуть сахара в чай, пожалуйста.
A little bit of sugar in the tea, please.
In this context, 'чуть' conveys 'a bit', indicating a small degree of improvement.