backstreet
Longman Dictionary of Contemporary English 5++LDOCE 5++back·street1 /ˈbækstriːt/ adjective [only before noun] SCLILLEGALbackstreet activities are done in a secret or illegal way, and are often done badly 秘密的，私下的，偷偷摸摸的〔通常指处理手法低劣〕 a backstreet abortion 非法堕胎
Examples from the Corpus
backstreet• A hot new pachinko machine from a backstreet maker in Osaka has taken the underworld by storm.backstreet2, back street noun [countable] a small quiet street that is away from the main part of a town 后街，偏僻街道Examples from the Corpus
backstreet• The other provides amazingly quick service - from an incomplete concrete house frame in a backstreet.• Three beer-befuddled construction workers played softball with my head in a backstreet on the mistaken assumption that I was Tom Tunney.• Frankie had left home and was now living in lodgings in a little backstreet near the pub they were sitting in.• One hour later the sonorous tones of Dame Melba's singing resonated through a little backstreet near the river.• From there, a quiet backstreet led to the rear entrance of her apartment block.back·street1 adjectivebackstreet2 nounChineseSyllable
secret backstreet or activities a in are Corpus done
backstreet
back‧street1 /ˈbækstriːt/ 
adjective [only before noun]
backstreet activities are done in a secret or illegal way, and are often done badly:
a backstreet abortion
backstreet2 , ˈback street noun [countable]
a small quiet street that is away from the main part of a town
| I |
adjective [only before noun]backstreet activities are done in a secret or illegal way, and are often done badly:
| II |
, ˈback street noun [countable]a small quiet street that is away from the main part of a town