第一人者

Etymology
A surface analysis would suggest that this is a compound of +. However, there is no such attested term.

Annotated in some sources as a compound of +. However, there does not appear to be any attested term.

Other sources list a pitch accent pattern indicating a compound of +. However, despite a listing for in the  Japanese Pronunciation Accent Dictionary, other monolingual Japanese references do not include any such term.

The term is first attested in 1907 as the title of a one-act play. The “best person” sense is not attested until 1918. There was an earlier term arising around 1688,  suggesting that the term  may ultimately be comprised of, with influence from the term.

Pronunciation

 * い・いんしゃ [dáꜜì ìchíníꜜǹshà] (Atamadaka + Nakadaka – [1][3])

Noun

 * 1)  the best or top person, such as the best performer in a company, or a leading expert