This is the 3309th most frequent Russian word.
очистить
"To clean" or "to clear."
In this case, 'очистить' is applied figuratively to signify correcting or purging undesirable elements, such as errors from a file.
Ему пришлось очистить файл от ошибок.
He had to clear the file of errors.
Here, 'очистить' refers to purifying or making a substance clean or suitable for use, specifically purifying water.
Очистить воду для питья можно с помощью фильтра.
Water for drinking can be purified using a filter.
Here, 'очистить' is used in the sense of physically cleaning or removing unwanted material from a surface, specifically dust from the table.