Pronunciation: [stˈand ˌɒn ˈɛnd] (IPA) 
The phrase "stand on end" refers to something that stands upright or becomes rigid. The spelling of the word "end" is straightforward, but the verb "stand" can be tricky. In IPA phonetic transcription, it is /stænd/. The "a" sound is pronounced like the "ae" in "cat", and the stress is on the first syllable. This phrase is often used to describe hair or fur that stands on end due to fear or excitement.
To stand on end means to become upright or erect suddenly, usually referring to hairs, fur, feathers, or bristles. When something stands on end, it typically stands more perpendicular to the body or surface it is attached to, creating a raised or bristled appearance. This expression is often used to describe an involuntary reaction to a strong emotion, such as fear, surprise, or excitement, which causes the hair to stand on end. It implies a physical response to a sudden rush of adrenaline or intense feelings that cause the body's hairs or fur to become erect.
When hairs or fur stand on end, it produces a distinctive visual effect, making an individual or creature appear larger or more menacing. This physiological response is often associated with fight or flight instincts triggered by perceived threats. Similarly, when feathers or bristles stand on end, it can indicate aggression or a defensive posture in animals, serving as a warning display to potential adversaries.
Metaphorically, the phrase "stand on end" can also be used to describe how something surprises, shocks, or captivates someone intensely. It expresses the idea of something causing a strong reaction or rendering someone speechless, as if their figurative hair were standing on end. In this sense, it conveys the notion of being deeply affected or moved by an unexpected or powerful experience or information.
