porous

The word 'porous' has a direct lineage from the Latin porus, which itself was borrowed from the Greek poros, meaning "passage, way, pore". The Greek term is traced back to the Proto-Indo-European root per-, a prolific root meaning "to lead, pass over", which also gives us words like 'port', 'portal', and 'ford'. The suffix -osus was a common Latin adjectival ending indicating abundance. Therefore, the literal construction "full of passages" evolved into the modern scientific and metaphorical meanings, describing any material or system that is permeable or easily penetrated.

Structure: por (passage, opening) + ous (adjective suffix) - por: From Latin porus, meaning "passage, pore, opening". Its functional role is to provide the core meaning of a small opening or passage. - ous: An English adjective-forming suffix, from Latin -osus, meaning "full of, characterized by". Its role is to convert the noun root into an adjective meaning "full of pores".