Lead-in to lingo Crossword Clue

 The answer to the crossword clue "Lead-in to lingo" is DUO. It is a 3-letter word.

The word "duo" means "two things or people considered together". It can also refer to a pair of musicians or singers who perform together. In the context of the crossword clue, "duo" is being used as a lead-in to the word "lingo", which means "a specialized vocabulary or jargon of a particular group or activity".

So, the answer to the clue is "duo" because it is a word that can be used to introduce the concept of lingo.

I hope this helps!