'staircase' originates from the combination of 'stair' and 'case', where 'stair' refers to a step or series of steps and 'case' refers to a surrounding structure.

'Staircase' evolved from the Middle English word 'steyrcas', which combined 'steyr' (stair) and 'cas' (case).

Initially, it referred to any structure containing stairs, and this meaning has largely remained the same in modern usage.