There are only ten words in English which end in "-vvy". Unfortunately there is nothing on the web about these words and about their formation. It's easy for example to guess how the word "Civvy" was created. "Civvy" looks to me like an abbreviation of the word civilian. Following the same pattern, "Bevvy" is an abbreviation of the word beverage and "Bivvy" is an abbreviation of the word bivouac. These new words are the result of the speakers' "rebellion" against the languange, against long words. It's the tendency of the colloquial English(and not only) to replace some of the long words with shorter ones. They say "time is money". There's no point wasting it while trying to pronounce neverending* words. In colloquial English, picture becomes "Piccy", cigarette becomes "Ciggy", television becomes "Telly" communist becomes "Commy" etc. Another wild guess of mine is that words such as communist, television, cigarette, beverage and civilian are still preferred to their shorter "siblings"in written English.
Let's have a look at the "-vvy" words allowed in Scrabble.
BEVVY = an alcoholic drink [n BEVVIES]to engage in a drinking session [v BEVVIED, BEVVYING, BEVVIES]
BIVVY = to go on a bivouac [v BIVVIED, BIVVYING, BIVVIES]
CIVVY = a civilian (a nonmilitary person) [n CIVVIES]
DIVVY= to divide (to separate into different parts) [v DIVVIED, DIVVYING, DIVVIES]
LUVVY= an entertainer, especially a camp one, also LUVVIE [n LUVVIES]
NAVVY= to work as a labourer [v NAVVIED, NAVVYING, NAVVIES]
SAVVY to understand [v SAVVIED, SAVVYING, SAVVIES]shrewd (having keen insight) [adj SAVVIER, SAVVIEST]
CHIVVY = to chase about, also CHEVY, CHIVY [v CHIVVIED, CHIVVYING, CHIVVIES]
SKIVVY = to work as a female servant [v SKIVVIED, SKIVVYING, SKIVVIES]
SPIVVY flashy (gaudy (tastelessly showy)) [adj SPIVVIER, SPIVVIEST]