:Extrametricality:

The situation where a syllable is ignored by a rule which assigns lexical stress. For example, part of the main stress rule in English (stated informally) specifies that the main lexical stress falls on the final syllable if it is heavy or on the penultimate syllable if the final syllable is light. This is true for many verbs and adjectives (but there are many exceptions). The situation for many nouns is different. The final syllable is ignored by the rule and the main stress falls one syllable earlier. Compare, for example, GB English contest (verb) kənˈtest and contest (noun) ˈkɒntest