This is the 645th most frequent Japanese word.
油
Oil.
Here, '油' is used to describe a type of lubricant necessary for machinery.
この機械には特別な油が必要です。
This machine requires special oil.
In this context, '油' pertains to oil-based paint used in art.
彼は油絵を描くのが得意です。
He is skilled at painting oil paintings.
In this sentence, '油' refers to cooking oil used in preparation of food items.