English Vocabulary Builder Practice Test 2026 - Free Vocabulary Practice Questions and Study Guide

A state of being pleasantly lost in one's thoughts is described by reverie. Reverie conveys a gentle, dreamlike bubble of contemplation—you’re mentally wandering and absorbed in pleasant thoughts, often with a calm, reflective mood. You can feel this in sentences like, “She drifted into a reverie while watching the sunset,” which signals an inward, enjoyable escape from the surrounding world.

This fits best because reverie names a specific emotional and mental condition—the act of daydreaming in a favorable, almost lyrical way. The other words point to things that aren’t about a reflective inner state: credulous means easily convinced; itinerant describes someone who travels from place to place; insuperable means impossible to overcome.