lineswomann.
/ˈlʌɪnzwʊmən/, U.S. /ˈlaɪnzˌwʊmən/ Sport (chiefly Tennis).
In games played on a field or court: a female official who assists the referee or umpire from the sideline or touchline, especially in deciding on whether the ball is out of play.
ΚΠ
1901 Boston Daily Globe 17 May 3/7 Miss Herrick was referee, Misses Blackwell and Macfarlane lineswomen, Miss Dinegan timekeeper.
1920 Amer. Lawn Tennis 15 Mar. 575/3 There were lineswomen instead of linesmen.
1969 Irish Times 5 July 3/3 A section of the crowd..pressurised a lineswoman into changing a call.
2009 A. Agassi Open xxv. 336 A lineswoman..reports me to the umpire.
This is a new entry (OED Third Edition, June 2017; most recently modified version published online March 2022).
<
n.1901