1 a period of 15 minutes before or after the hour -- quarto
We’re leaving at quarter past six (= 6.15). Partiamo alle sei e un quarto.
It’s quarter to three (= 2.45). Manca un quarto alle tre.
2 a coin with a value of 25 cents (= 25/100 of a dollar) in the US and Canada -- quarto di dollaro, moneta del valore di 25 cents in USA e Canada
There are four quarters in a dollar. Ci sono quattro quarti di dollaro in un dollaro.
3 one of four time periods that a year can be divided into -- trimestre
4 to cut something into four parts -- dividere in quattro, ridurre a un quarto
5 one of four equal parts of something which together form the whole (amount) of the thing -- quarto