A diffuser nozzle for a gas turbine engine, the diffuser nozzle comprising: a housing disposed about a nozzle axis and extending between a first nozzle end and a second nozzle end, the housing comprising a nozzle inlet located at the first nozzle end and a nozzle outlet located at the second nozzle end, the housing defining a nozzle duct extending from the nozzle inlet to the nozzle outlet; and a plurality of walls disposed within the nozzle duct, the plurality of walls subdividing the nozzle duct into a plurality of duct sections (74A-D) with each duct section of the plurality of duct sections (74A-D) extending from the nozzle inlet to the nozzle outlet and having a duct cross-sectional area, the plurality of walls further defining a plurality of axially-extending duct segments (88A-D) of the nozzle duct, the diffuser nozzle being characterised in that within a first axially-extending duct segment of the plurality of axially-extending duct segments (88A-D), the duct cross-sectional area of a first duct section of the plurality of duct sections (74A-D) is greater than the duct cross-sectional area of each other duct section of the plurality of duct sections (74A-D), and within a second axially-extending duct segment of the plurality of axially-extending duct segments (88A-D), the duct cross-sectional area of a second duct section of the plurality of duct sections (74A-D) is greater than the duct cross-sectional area of each other duct section of the plurality of duct sections (74A-D). a housing disposed about a nozzle axis and extending between a first nozzle end and a second nozzle end, the housing comprising a nozzle inlet located at the first nozzle end and a nozzle outlet located at the second nozzle end, the housing defining a nozzle duct extending from the nozzle inlet to the nozzle outlet; and a plurality of walls disposed within the nozzle duct, the plurality of walls subdividing the nozzle duct into a plurality of duct sections (74A-D) with each duct section of the plurality of duct sections (74A-D) extending from the nozzle inlet to the nozzle outlet and having a duct cross-sectional area, the plurality of walls further defining a plurality of axially-extending duct segments (88A-D) of the nozzle duct, the diffuser nozzle being characterised in that within a first axially-extending duct segment of the plurality of axially-extending duct segments (88A-D), the duct cross-sectional area of a first duct section of the plurality of duct sections (74A-D) is greater than the duct cross-sectional area of each other duct section of the plurality of duct sections (74A-D), and within a second axially-extending duct segment of the plurality of axially-extending duct segments (88A-D), the duct cross-sectional area of a second duct section of the plurality of duct sections (74A-D) is greater than the duct cross-sectional area of each other duct section of the plurality of duct sections (74A-D). the diffuser nozzle being characterised in that within a first axially-extending duct segment of the plurality of axially-extending duct segments (88A-D), the duct cross-sectional area of a first duct section of the plurality of duct sections (74A-D) is greater than the duct cross-sectional area of each other duct section of the plurality of duct sections (74A-D), and within a second axially-extending duct segment of the plurality of axially-extending duct segments (88A-D), the duct cross-sectional area of a second duct section of the plurality of duct sections (74A-D) is greater than the duct cross-sectional area of each other duct section of the plurality of duct sections (74A-D).