Wiktionary
plough on
vb. To continue with a task despite it being menial, difficult, or boring
WordNet
Usage examples of "plough on".
And they fell to wondering how a man could live in the hot terrible Plains where the cattle run as big as elephants, unfit to plough on a hillside.
He got up and went to the bar, wondering how he was going to plough on through this and other evenings.
Schaffer surveyed the massive steel plough on the front of the bus and shook his head sorrowfully.
So why would he choose to ignore the tone and meaning that he knows Tom wishes to convey and plough on regardless?
When at length they reached plough on the right hand and open pasture on the left Stephen said, 'One of the advantages of life at sea, for men of our condition, is freedom of speech.