necking

Necking is a term with two common uses in English. In everyday language, necking denotes a form of intimate behavior between two people, often involving kissing and caressing of the neck and surrounding areas. In scientific and engineering contexts, necking describes a localized reduction in a material’s cross-sectional area under tensile loading, preceding fracture. The two uses are unrelated etymologically but share the idea of focusing action at a constrained region.

Romantic necking typically occurs in private or semi-private settings and emphasizes non-penetrative contact. The intensity and boundaries vary by culture, relationship, and consent. In cultural discussions of media and dating, necking has been used as a shorthand for physical affection short of full sexual activity.

In materials science, necking occurs in ductile materials after yielding when deformation concentrates at a weakest cross-section. The neck reduces cross-sectional area and local strain increases until fracture. On the engineering stress-strain curve, necking begins at the peak engineering stress; beyond this point, true stress continues to rise while engineering stress declines. Necking is influenced by material properties, temperature, and rate of loading, and it informs design limits to avoid premature failure.