1. To walk, especially for a long distance, especially in the countryside: This is the most common meaning of "hike." For example: "We went for a hike in the mountains."
2. To increase something, usually a price or a fee: For example: "The company hiked its prices by 10%."
3. To raise something, usually a flag: For example: "The soldiers hiked the flag."
4. To move something upwards: For example: "He hiked the suitcase onto the luggage rack."
The specific meaning of "hike" will be clear from the context in which it is used.