Definition of wallahs:
(n) :
(North India) A servant or other person responsible for something, often specified before it, for example kitchen wallah.
(n) :
(British, slang) A guy or bloke.
(adv) :
(Islam) by God (Allah); may God be my witness. Used in making a solemn oath
(n) :
(North India, historical) Ellipsis of competition wallah. [(India, historical, colloquial) A member of the civil service who obtained an appointment by the competitive system instituted in 1856.]