noun

die Blase, -n

bladder · blister · bubble

(Anatomy/Medicine) bladder
The organ that stores urine (Harnblase), or more generally a sac-like organ (e.g., Gallenblase = gallbladder).
(Everyday/Physical) bubble / blister
- Bubble: an air/gas pocket in a liquid or material (e.g., soap bubble, air bubble).
- Blister: a fluid-filled bubble on the skin from friction or burns (often specified as Brandblase or Wasserblase).
(Figurative/Economics/Society) bubble (as in “economic/social bubble”)
A situation of isolation or distortion, e.g. a market bubble (Spekulationsblase) or living in a “bubble” (in einer Blase leben).

Blase is a basic noun; historically related to ideas of “blowing/inflating” (a swollen, inflated sac).
Common compounds:
- Harnblase = urinary bladder
- Gallenblase = gallbladder
- Seifenblase = soap bubble
- Wasserblase = blister (water blister)
- Luftblase = air bubble
- Spekulationsblase / Immobilienblase = speculative/real-estate bubble

Bladder (Harnblase): Harnblase (more specific), Blase (general)
Bubble: Luftblase (air bubble), Seifenblase (soap bubble), sometimes Bulle (regional/rare)
Blister (skin): Wasserblase, Brandblase
Figurative “bubble”: Filterblase (esp. online), Echokammer (related concept)

No single direct antonym fits all meanings. Depending on context:

For bubble/blister (something inflated): Leere, Vakuum (conceptual opposites in some contexts)
For figurative bubble (isolation): Realitätsnähe, Offenheit, Außenweltkontakt (conceptual opposites)