Synonyms: plug away, peg away, keep one's nose to the grindstone, keep one's shoulder to the wheel, slog
Definition: work doggedly or persistently
Usage: She keeps plugging away at her dissertation
Similar words: work
Definition: exert oneself by doing mental or physical work for a purpose or out of necessity
Usage: I will work hard to improve my grades; she worked hard for better living conditions for the poor