Whenever you leave your home, walk from one room to another, or enter a building, you are crossing a threshold—that is, the horizontal floor piece that you cross over whenever you …

Idiom on the threshold of something (Definition of threshold from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

on/at the threshold : at the beginning of something or very close to something (such as a new condition, an important discovery, etc.) — usually + of young people on the threshold of …

A threshold takes you from one place into another, and when you're about to start something new, you're also on a threshold. A threshold is a point of departure or transition.

A threshold is an amount, level, or limit on a scale. When the threshold is reached, something else happens or changes.

Also called limen. the point at which a stimulus is of sufficient intensity to begin to produce an effect: the threshold of consciousness; a low threshold of pain.

Threshold definition: the sill of a doorway.. See examples of THRESHOLD used in a sentence.

any point of beginning: He was on the threshold of a new career. Physiology, Psychology the point at which something begins to take effect: Her dream was hovering on the threshold of …

There are 11 meanings listed in OED's entry for the noun threshold, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

Synonyms for THRESHOLD: verge, brink, edge, cusp, point, nick, beginning, start; Antonyms of THRESHOLD: end, close, conclusion, period, ending, completion, closing, termination