IPA: /ˌsɛmi.oʊˈpeɪk/
KK: /sɛmiˈoʊpeɪk/
Partially allowing light to pass through, but not completely clear.
The curtains are made of a semiopaque material that lets in some light while still providing privacy.
Semiopaque → It is formed from "semi-" (meaning half) and "opaque" (from Latin "opacus", meaning dark or not transparent). The word "semiopaque" describes a material that is half transparent, allowing some light to pass through while blocking the rest.
Think of 'half' ('semi-') and 'not transparent' ('opaque') to remember that 'semiopaque' means something that allows some light through but not completely.
No commonly confused words.