This is the 3971st most frequent Arabic word.
بكأس
"بكأس" means "with a cup."
The word 'بكأس' in this sentence is used to indicate the instrument (a cup) used to drink the juice.
شربت عصيرًا بكأس زجاجية.
I drank juice from a glass cup.
Here, 'بكأس' signifies the awarded object (a cup) given to the winner.
كرّم الفائز بكأس ذهبية.
The winner was honored with a golden cup.
In this case, 'بكأس' refers to the object (a cup) with which the action, playing, was associated.