Grace is that aspect of divine action by which God blesses his rebellious creatures, whether through preservation (common grace) or salvation (special grace). It characterizes the manner in which he deals with those who through their rejection of him as their Creator and sovereign deserve nothing from him and yet whom he still chooses to bless.
Trueman, Carl R.; Trueman, Carl R.. Grace Alone—Salvation as a Gift of God: What the Reformers Taughts…and Why It Still Matters (The Five Solas Series) (p. 25). Zondervan. Kindle Edition.