Recession is the declining phase on the traditional boom-bust model, essentially when trade and industry are reduced
Inflation is when currency becomes devalued proportional to the global price of goods and services; the opposite of this would be a liquidity crisis. You do not need a fiat currency to experience inflation; it is not when "printer go brrr". Inflation just requires the currency of a state or entity to lose value in some way. The pre-fiat currencies of the medieval world experienced horrible inflation during wars and conflicts, when a large chunk of the state's treasury would be needed to raise large armies.