In this case it seems to. It’s the first time I recall encountering it but I’m not British and my parsing of unfamiliar and ‘rough’ accents is such that if I happened to have heard someone say ‘squid’ I may have parsed it as ‘quid’, and discarded the ‘s’ as noise from people saying a familiar term in a weird way rather than a different term.
Does Cockney rhyming slang not count as slang?
In this case it seems to. It’s the first time I recall encountering it but I’m not British and my parsing of unfamiliar and ‘rough’ accents is such that if I happened to have heard someone say ‘squid’ I may have parsed it as ‘quid’, and discarded the ‘s’ as noise from people saying a familiar term in a weird way rather than a different term.