This is the 756th most frequent Turkish word.
yarı
"Yarı" means "half" in English.
In this sentence, 'yarısı' (a form of 'yarı') means 'half', referring to one of two equal time segments of the match.
Kupa maçının ilk yarısı çok heyecanlı geçti.
The first half of the cup match was very exciting.
Here, 'yarı' refers to something being partial, implying incomplete or partial lighting.
Gün ışığının yarı aydınlattığı odada oturuyordu.
He was sitting in the room half-lit by sunlight.
In this context, 'yarı' denotes a proportion or fraction, indicating being half of his heritage is Turkish.