This is the 226th most frequent Hebrew word.
מפני
Because of / Due to.
In this sentence, "מפני" is used to indicate a reason or cause, functioning as "because".
אני סוגרת את החלון מפני שקר.
I am closing the window because it is cold.
Here, "מפני" explains the reason for not eating the cake, used similarly to "because" in English.
לא אכלתי את העוגה מפני שהייתי מלאה.
I didn't eat the cake because I was full.
"מפני" here implies a cause or reason for the action, acting as "due to" in this context.