IPA: /ˌspɛkjʊˈlærɪti/
KK: /spɛkjuˈlærɪti/
The state or quality of reflecting light in a way that creates a shiny or mirror-like surface.
The specularity of the water's surface made it look like a mirror reflecting the sky.
Specularity is formed from "specularis" (meaning of mirrors or reflecting) and the suffix "-ity" (meaning the state or quality of). The word refers to the quality of being like a mirror or reflecting light.
Think of 'specularis' which relates to mirrors, and remember that 'specularity' means the quality of reflecting like a mirror.