IPA: /æpˈtɛr.i.ə/
KK: /ˈæptəriə/
The bare areas on a bird's body where feathers do not grow, often found between feathered regions.
The apteria on the bird's wings are clearly visible when it spreads them.
Apteria is derived from the Greek word "apteron" (meaning wingless), which is composed of the prefix "a-" (meaning without) and "pteron" (meaning wing). The term "apteria" refers to a condition or state of being without wings.
Think of 'without' ('a-') and 'wings' ('pteron') to remember that 'apteria' describes something that is wingless.