IPA: /ˈreɪl.kɑːrd/
KK: /ˈreɪlˌkɑrd/
A card that gives you discounts on train tickets, making travel by train cheaper.
I bought a railcard to save money on my train journeys.
Railcard → The word is formed from "rail" (from Old French *raille*, meaning a bar or rod) and "card" (from Latin *charta*, meaning a piece of paper or document). A railcard is a card that provides access to rail services, thus combining the concepts of a rail system and a card for identification or access.
Think of a 'rail' as a bar for trains and a 'card' as a document that gives you access — a railcard is your ticket to ride the rails.