This is the 1446th most frequent Japanese word.
珈琲
Coffee.
Here, '珈琲' is used as a noun, referring specifically to the beverage coffee. It is the object of the verb '飲みます' (to drink).
朝食には珈琲を飲みます。
I drink coffee for breakfast.
'珈琲' is used as a noun describing the substance related to the beans being researched ('豆'). It is part of a larger noun phrase ('珈琲の豆').
彼の趣味は珈琲の豆を研究することです。
His hobby is researching coffee beans.
'珈琲' serves as a noun denoting coffee as the entity being evaluated ('最高です', meaning 'is excellent').