| English | Catalan |
| high mountain | alta muntanya |
| high protein food | aliment alt en proteïnes |
| high-rise building Any tall, multistoried structure or edifice that is equipped with elevators | edifici de gran alçada |
| high-speed railway The term "high-speed traffic" encompasses all trains running at speeds over 200 km/h but also trains running at 200 km/h if the terrain, population density or economic reasons do not justify higher speeds | ferrocarril d'alta velocitat |
| high-speed train Trains travelling at maximum speeds of 300kmh on special high-speed rail lines | trens d'alta velocitat |
| high tide water The level of water when the tide is at its highest level | plenamar |
| high voltage line An electric line with a voltage on the order of thousands of volts | línia d'alta tensió |
| higher education Study beyond secondary school at an institution that offers programs terminating in undergraduate and graduate degrees | ensenyament superior |