Adventurers spend a lot of time in dungeons which is a term used in Dungeon World for dragon's caves, enemy camps, sky castles, sunken temples- any place filled with danger and opportunity. Dungeons are living places filled with creatures who are going to move around and react to what you are doing. Don't take anything for granted in a dungeon.
Be prepared for the long haul. Rations are your friend. Goblins aren't tough but when they have time to rally and prepare traps... keep your eyes open for traps even in dungeons without goblins. Remember to Supply with rations and other Dungeon Gear whenever you are is a steading .
The scary, hungry and/or well-armed creatures that dwell in dungeons? Those are monsters. Not all of them are going to attack on sight. But fighting monsters is the bread & butter of being an adventurer and it is really hard work. Fighing often means triggering moves like Hack & Slash, Defend, Volley and Defy Danger.