Present participle of 'circularise': the act of making circular or distributing information to many people (British spelling).
From 'circularise' plus '-ing,' the gerund and present participle suffix. The '-ing' suffix comes from Old English '-ung' and is used to create nouns from verbs or to show ongoing action.
The '-ing' ending is one of English's superpower suffixes—it can turn almost any verb into a noun, adjective, or continuous action, making language incredibly flexible and efficient.
Complete word intelligence in one call. Free tier — 50 lookups/day.