A Lexical Gap, also known as an Accidental Gap, is the concept whereby one language has a word for a particular thing, yet another language somehow manages to scrape by without a word for that thing, or maybe it has a word that denotes that thing, but that same word also denotes something else altogether.
A famous example in Latin is the adjective fortis, forte, which means 'brave' or 'strong'. I don't know about you, but I can easily conceive of a man or woman who is brave, but yet not strong. Equally, I am able to wrap my brain around the possibility of a man or woman who is strong, but yet not brave.
But apparently the ancient Romans could not. Context alone determines which meaning is appropriate when translating.
Another fun example in Latin is the adjective ignavus, ignava, ignavum. The word can mean. alternately, 'lazy' or 'cowardly'. I mean, we can try to posit a scenario in which a lazy centurion does not respond to an attack and his laziness essentially amounts to cowardice. But, to be honest, these are still different, and potentially mutually exclusive, conditions.
By an accident of romance, I have had to learn Romanian. And Romanian contains its own fun Lexical Gaps.
Romanian does not have a word for "shallow." If you ask a Romanian how to say "shallow," they will curl their eyebrows and then finally offer, "nu adânc" (not deep).
But most fun of all, and I was prompted to write this post because I stumbled on this adjective while studying Romanian in preparation for a New Year's Party in which I will soon be expected to speak nothing but that language for several hours, is the adjective gol, goală, goi, goale.
This adjective means both 'naked' and 'empty'. That's right, an empty bottle is o sticlă goală. A naked woman is o femeie goală.
Those really were random examples my brain produced for this lexical discussion. Don't hate me...
Hmm... Isn't it interesting that all of these Lexical Gaps I cited involve adjectives? I will not dig further, choosing to leave some meat on the bone for junior linguists.