Origin of "stop-gap"

What is the origin of the expression stop-gap?

stop-gap: A temporary way of dealing with a problem or satisfying a need

Where and how did this expression originate?

Solution 1:

According to dictionary.com, stopgap is an adjectival use of the verb phrase "stop a gap" (meaning, essentially, plug a hole) and emerged around 1525-1535.

Merriam-Webster, though, has the first known use as 1684.

Google Ngrams shows "stopgap" appearing briefly in the 1700s and disappearing again until the middle of the 1800s, at which point its use took off pretty dramatically, with a slight taper in the past 60 years.