1. A solid material that has a porous or loose structure with internal voids, gaps, or spaces that are not completely filled
Foam and pumice are examples of non-compact solids that have low density despite their solid appearance.
Espuma e pedra-pomes são exemplos de sólidos não-compactos que possuem baixa densidade apesar de sua aparência sólida.
2. In mathematics and topology, a solid that is not compact in the topological sense, meaning it is not both closed and bounded
An infinite cylinder is a non-compact solid in mathematical topology.
Um cilindro infinito é um sólido não-compacto na topologia matemática.