Language, especially language peculiar to a particular group, field, or region; jargon or a dialect.
"The new intern struggled to keep up because everyone in the marketing department spoke in confusing lingo that only made sense after months on the job."
A surname.
"The new coach, Mr. Lingo, arrived at the practice wearing his signature red cap."
The word lingo comes from the Latin word lingua, meaning "tongue" or "speech," combined with a diminutive suffix. This origin reflects its original sense of referring to a specific, often small-scale, variety of language.