1 chief, primary, prime, (most) important, principal, cardinal, paramount, first, foremost, leading, pre-eminent, predominant, predominating, dominant, ranking, major; outstanding:
The main cause of traffic deaths is drunken driving. In Britain, the main street of a town is called 'the High Street'. We arrived late and missed the main entertainment.
2 largest, biggest, greatest, strongest:
The main part of the strike force landed in Normandy.
3 necessary, essential, basic, particular, fundamental, critical, crucial, vital:
Economic recovery is the main thrust of our programme for reform.
4 sheer, brute, utter, pure, out-and-out, absolute, mere, plain:
He lifted that block by main force!
5 pipe, duct, channel, line, pipeline, water or gas main, Brit (electric) cable, mains, power (supply), conduit:
Water reaches the city through a huge underground main.
6 strength, power, might, effort, energy, vigour:
With all his might and main he tried to move the stone blocking the cave
in the main. See mainly
in the main, chiefly, principally, predominantly, generally, above all, on the whole, in general, mostly, most of all, effectively, essentially, at bottom, first and foremost, for the most part, largely, by and large, primarily, as a rule, usually, all in all, on balance, for all practical purposes, in the long run:
We are concerned mainly with safety. The tourists are mainly from Italy.