also: よっか
noun, noun which may take the genitive case particle 'no'
under the wing (of an aircraft)
Literal spatial location beneath an aircraft's wing. Often used in aviation contexts.
翼下のエンジンから煙が出ている。
Smoke is coming from the engine under the wing.
noun, noun which may take the genitive case particle 'no'
under one's wing; under one's control
Figurative use: being protected, guided, or controlled by someone. Often used in phrases like 翼下に入る or 翼下に置く.
彼は先輩の翼下で仕事を覚えた。
He learned the job under his senior's wing.
その会社は大企業の翼下に入った。
The company came under the wing of a large corporation.
傘下 means 'under the umbrella' and is used for subsidiaries or affiliates of a larger organization, while 翼下 is more personal and protective, like a mentor or guardian.
Compound of 翼 (wing) and 下 (under). The figurative sense is a calque from English 'under one's wing'.