Definition
A reinforcing ring, usually made of rubber, plastic, or metal, fitted into a hole in a panel, sheet, or fabric to protect wires, cables, or hoses passing through it from chafing against the edges of the hole.
Plain English
A small ring lining a hole so that whatever passes through it doesn't rub against the sharp or rough edge.
Context Anchor
Seen during aircraft inspection, maintenance, and wiring or tubing installations where something passes through a panel, rib, firewall, or other aircraft structure.
Derivation
From the French 'gourmette,' meaning a small chain or curb. The word came into English to describe small reinforcing rings, and the aviation use follows that same idea: a small ring that strengthens and protects.
Why Pilots Care
Prevents abrasion damage that could lead to electrical shorts or fluid leaks.
Analogy
A grommet is like the smooth plastic ring around a hole in a desk that keeps computer cables from scraping on the sharp edge.
Intuition Check
A grommet is not the wire, tube, or cable itself. It is the protective ring around the hole that the wire, tube, or cable passes through.
Example Sentence 1
During the preflight inspection, the mechanic noticed the rubber grommet around the wiring bundle had hardened and cracked, so it was replaced before the next flight.
Example Sentence 2
During the inspection, check the grommets around control cables for wear that might allow chafing.