lifeguard

Noun

lifeguard (plural lifeguards)

1. A lifesaver: a rescuer, usually an expert swimmer, employed to save swimmers in trouble or near drowning at a body of water.
   • It's also generally wise to recruit lifeguards to ensure visitor safety, as bathers can panic in the water and require assistance.2025 February, Rick Lane, “Review: Planet Coaster 2”, in PC Gamer (US), number 392, page 67; published online 1 November 2024
2. (uncommon) A bodyguard or unit of bodyguards, a guard of someone's (especially a king's) life or person.
   • "The people's love is the king's lifeguard."1776, The London Magazine, Or, Gentleman's Monthly Intelligencer
   • [I]n the reserve were the king's lifeguard, commanded by the earl of Lindsey, and prince Rupert's regiment of foot[.]1843, Edward Hyde, The History of the Rebellion and Civil Wars in England, page 553
3. A sturdy metal bracket fixed in front of each of the leading wheels of a train to deflect small objects away from the wheels to prevent derailment.
   • It also looked at what effect stronger lifeguards might have had. They protect the leading wheels from small obstacles and in modern trains have coped with hitting landslip debris.2022 March 23, Philip Haigh, “Network News: Driver of ScotRail HST had only seconds to react, says RAIB”, in RAIL, number 953, page 11