IPA: /ˈtʃiːfli/
KK: /ˈtʃifli/
Not applicable as 'chiefly' is not an adjective; it is an adverb that means mainly or primarily.
The project was chiefly funded by private donations.
This word is used to indicate that something is primarily or mostly true, or to emphasize the most important aspect of something.
The project was chiefly focused on improving community health.
Chiefly → It is formed from "chief" (from Old French *chief*, meaning leader or head) and "-ly" (meaning in the manner of). The word "chiefly" means in the manner of a leader or primarily.
Think of someone who is a 'chief' or leader, and remember that 'chiefly' means primarily or mainly, as if it is in the manner of a chief.