- linesman - official (in tennis or soccer or football) who assists the referee is some way (especially by watching for off-sides or out of bounds)
--1 is a kind of official
- electrician, lineman, linesman - a person who installs or repairs electrical or telephone lines
--2 is a kind of skilled worker, trained worker
--2 has particulars: gaffer - electrician, lineman, linesman - a person who installs or repairs electrical or telephone lines