first-string

The compound 'first-string' originates from the world of sports, particularly archery and later team sports. Literally, it refers to the foremost line or rank, such as the primary line of players on a sports field. The term 'string' metaphorically extends from its original meaning of a cord or line to denote a sequence or tier of team members. Over time, its meaning evolved from a purely positional descriptor to signify the regular starting players of a team and, by further extension, anything of the highest quality or rank.

Structure: first (foremost) + string (line) - first: From Old English fyrst, foremost. Functions as a numeral adjective indicating position before all others. - string: From Old English streng, line, cord. Functions as a noun, here used metaphorically to denote a series or sequence, specifically a line of players.