salt
n.— «With that, Madrid became what’s called “a salt”: a union employee who infiltrates nonunion work sites. His work is part of a larger effort by New Orleans trade unions to combat what they call an underground cash-only economy fueled by the post-Hurricane Katrina construction boom.» —“Migrant workers fleeced, union says” by Katy Reckdahl in New Orleans, Louisiana Houston Chronicle (Texas) Aug. 18, 2007. (source: Double-Tongued Dictionary)
Further reading
We asked for your thoughts about whether cursive writing should be taught in schools — and many of you replied with a resounding “Yes!” You said cursive helps develop fine motor skills, improves mental focus, and lets you read old...
Secret signals on the job: Waitresses at some 19th-century restaurants ensured speedy drink service by communicating with a non-verbal code. One server took orders, then placed each customer’s cup to indicate exactly what the customer wanted...