IPA: /ˈlʌnʧruːm/
KK: /ˈlʌnʧrum/
A room where people can eat lunch, often found in schools or workplaces, where meals can be bought or brought from home.
Students gather in the lunchroom to eat and socialize during their break.
Lunchroom → It is formed from "lunch" (originating from the 17th century, possibly a diminutive of "luncheon", which means a light meal) and "room" (from Old English "rum", meaning space or area). The word "lunchroom" refers to a room designated for having lunch or a light meal.
Think of a 'light meal' ('lunch') being enjoyed in a designated 'space' ('room') — that's what a lunchroom is.
No commonly confused words.