This is the 430th most frequent Hebrew word.
שנת
The Hebrew word "שנת" can mean "year of" or "sleep" depending on context.
Here, 'שנת' is the construct form of the Hebrew word for 'year' (שנה), used when describing a specific type of year.
שנת הלימודים מתחילה בספטמבר.
The school year starts in September.
'שנת' here is the construct form indicating possession or relation, describing 'night's sleep' as related to the night.
אני מקווה שתהיה לך שנת לילה טובה.
I hope you have a good night's sleep.
In this example, 'שנת' is used in its construct form to attach to a specific year.