Fastest and Light-headed

Fastest adverb - Most quickly.

Light-headed and fastest are semantically related. In some cases you can use "Light-headed" instead an adjective "Fastest".

Light-headed adjective - Having a feeling of being whirled about and in danger of falling down.

Fastest and light-headed are semantically related. Sometimes you can replace term "Fastest" with "Light-headed", this terms are similar.