Adjective
not made dim or less bright
Source: WordNetThe real meaning of enlightenment is to gaze with undimmed eyes on all darkness. Nikos Kazantzakis
undimmed headlights Source: Internet
surprisingly the curtain started to rise while the houselights were still undimmed Source: Internet
Therefore, O Lord, we pray you that this candle, hallowed to the honor of your name, may persevere undimmed, to overcome the darkness of this night. Source: Internet
The Exultet concludes with a blessing of the candle: Accept this Easter candle, a flame divided but undimmed, a pillar of fire that glows to the honor of God. Source: Internet