noun
false bottom; raised bottom; platform (shoes); kick (of a bottle)
Refers to a structure that creates a higher internal floor than the external bottom, used for deceptive packaging, shoe lifts, or bottle design.
この箱は上げ底になっていて、中身が少なく見える。
This box has a false bottom, making the contents look smaller.
彼は身長を高く見せるために上げ底の靴を履いている。
He wears platform shoes to look taller.
noun
Figurative use derived from the physical false bottom; implies making something seem greater than it is, often in speech or claims.
彼の話はいつも上げ底で、どこまで本当かわからない。
His stories are always exaggerated; I never know how much is true.
Rare spelling; 上 means 'upper' and 底 means 'bottom', but this combination is uncommon.
Alternate kanji spelling; 揚げ can suggest 'fried' but is used here for the raised bottom meaning.
Rare abbreviated spelling.
底上げ means 'raising the bottom' in the sense of improving the lowest level or standard, not a deceptive false bottom.
Compound of 上げ (age, 'raising') + 底 (soko, 'bottom'), with rendaku voicing to ぞこ. The figurative sense of 'exaggeration' comes from the idea of artificially raising the bottom to make something appear larger.