Dale, As far as I can tell you should have no fear of anyone mistaking the common sense of ‘minging’ (1970, British slang for ‘stinking,’) with the purported ‘mincing’ sense. Also, this isn’t a hot new word of the variety you might be interested in for your dictionary – it’s been around in its present form for over 30 years.
I did find ‘mince’ mentioned in a few places supposedly traceable back to Webster’s 1913 dictionary, but I checked and it is not there. I don’t know where these few dictionaries dug up the idea that there was a connection to ‘mince,’ but no reputable sources that I checked said anything about that and I could not find any examples of it ever being used in that sense. So it appears to me that the ‘metamorphosis’ you speak of probably is not taking place, or if it is it is so esoteric that mere mortals would never notice it.
According to the sources that I checked MINGING first appeared in print in 1970 (see quote below) as a slang adjective, which was said to be originally Scottish. It means smelling bad, stinking, rank, but more generally, unpleasant, foul, or very drunk. It derives from the earlier Scottish noun MING (1923), which originally meant human excrement, but the usual sense of which has become ‘an unpleasant smell.’ Interestingly, MINGO was 18th to mid-19th century U.S. campus slang for ‘chamber pot,’ but it is uncertain if this was connected to the Scottish senses. MING also emerged in the 1970s as a verb meaning ‘to stink’ and a MINGER was one who literally or figuratively smelled. By 1995 a MINGER had become British slang for an ugly or unattractive person, especially, but not necessarily, a woman.
It should also be noted that ‘ming’ as a verb and a noun has several other meanings including ‘to mix or blend one thing with another,’ which is related to the word ‘mingle.’
<1923 “‘MENG,’ human excrement.”—‘Roxburghshire Word-Book’ by G. Watson, page 210>
<1970 “They were ‘MINGIN’ or ‘Pissed’—the state before complete drunkenness.”—‘Scottish Daily Express,’ 20 August, page 5>
<1985 “MINGIN means stinking but can also be used to describe anything bad: ‘We just came hame early cause the weather was MINGIN.’”—‘Patter’ by M. Munro, page 46>
<1989 “‘MINGING’. . . (‘Royal Marines’). Adopted Glaswegian slang word meaning drunk: ‘Jus' two beers an' the boy was MINGIN'.’ . . . It can also mean smelling strongly: ‘Three weeks ashore in the Falklands an' we was all MINGING pretty bad.’”—‘Jackspeak’ by R. Jolly, page 186>
<1997 “Daddy, a man swam the Danube for me! Are you proud? It's full of MINGING ex-communist pollution.”—‘These Demented Lands’ by A Warner, page 184>
<1998 “I open my overcoat and flap it to see if the MING is as steadily rancid as I imagine it to be.”—‘Filth’ by I Welsh, page 35>
<2000 “Sturrock called United's first half unacceptable. MINGING was nearer the mark.”—‘Scottish Sun’ (Super Goals), 21 February. page 3/2>
(Oxford English Dictionary, Cassell’s Dictionary of Slang
Ken G – December 28, 2004
Reply from Ken Greenwald (Fort Collins, CO - U.S.A.)