the second of two or the second mentioned of two
"Tom and Dick were both heroes but only the latter is remembered today"
referring to the second of two things or persons mentioned (or the last one or ones of several)
"in the latter case"
Relating to or being the second of two items.
"When choosing between the red and blue shirts, I decided to go with the latter because it fits better."
In plain English: Latter means the second of two things you are talking about.
"The latter option is cheaper, so I decided to choose it."
Usage: Use "latter" only when referring specifically to the second of exactly two previously mentioned items. It should not be used with groups containing more than two things or without clear prior reference to a pair.
Latter comes from the Old English word laetra, which was originally the comparative form meaning "later." It entered Middle English as a distinct term for the second of two things mentioned, separate from its modern usage as simply a synonym for later.