chiefly

Chiefly is an adverb that means mainly, principally, or for the most part. It is used to indicate the primary focus, aim, or characteristic of something, while leaving room for lesser aspects or exceptions. In sentences, chiefly modifies a noun phrase or a clause; it often comes before the element it qualifies, as in "The report focuses chiefly on education policy," and can be placed at the end, as in "The report focuses on education policy, chiefly." However, the latter is less common.

Etymology: The word derives from chief, meaning principal or head, from Old French chef and ultimately Latin caput. The adverbial suffix -ly forms adjectives into adverbs in Middle English.

Usage notes: Chiefly is somewhat formal and more often found in written or careful speech than in casual conversation. It conveys a stronger emphasis on the main aspect than "mainly" or "primarily" and often signals that other elements exist but are subordinate.

Examples: The project was successful, chiefly due to its strong funding and community support. The work will address several issues, chiefly economic policy and healthcare costs.

In modern English, chiefly is a useful hedge for indicating the primary cause or feature without asserting total exclusivity. It is often used in academic, policy, and journalistic writing.