ETOPS (Extended range operations for two engine aeroplanes)

ETOPS operations are those with two engine aeroplanes approved by the Authority (ETOPS approval), to operate beyond the threshold distance determined in accordance with Maximum distance from an adequate aerodrome for two-engined aeroplanes without an ETOPS approval from an Adequate Aerodrome.

Source: EU-OPS

See also:
Adequate ETOPS en-route alternate aerodrome
Approved one-engine-inoperative cruise speed
ETOPS (Extended range operations for two engine aeroplanes)
ETOPS area
ETOPS planning minima
Types of ETOPS En-Route Alternates