Origin of the Term "Shamus"
The noun "shamus" denotes someone skilled at uncovering secrets or gathering information. Its origin traces back to the Yiddish "shammes".
Irish Connection
In the early 20th century Irish-Americans predominated US police forces. Their prevalence possibly alludes to the Irish name Seamus. This likely led to the slang use of "shamus" for a police officer.
Usage and Meanings
A "shamus" is a private detective or investigator. The term’s origin is obscure but it was popularized in the 1920s, especially in crime fiction.
Why are detectives called Shamus? Perhaps from the common Irish name Séamus, James (from the many Irish Americans who traditionally served on American police forces), or from shammes (the duties of a detective being likened to those of a shamash).
Gumshoes Mean Private Detectives
What does the term gumshoes mean? To work as a detective. To go softly, as if wearing rubber shoes; move or act snoopily or stealthily.
Detectives should always wear lace-up shoes, not loafers that could easily slip off the feet just when you need them the most. No leather soles, if possible. And female detectives should never, ever wear heels.
Gumshoe, a slang term for a private detective, from those that wore street shoes with a thick, soft and quiet rubber sole.
Seamus Name Information
Is Seamus Irish or Scottish? Seumas Scottish Gaelic pronunciation: [ˈʃeːməs] is a masculine given name in Scottish Gaelic and Scots, equivalent to the English James.
Seumas Scottish Gaelic pronunciation: [ˈʃeːməs] is a masculine given name in Scottish Gaelic and Scots, equivalent to the English James.