noun (plural focuses or foci /ˈfəʊsʌɪ/)
- Geology the point of origin of an earthquake. Compare with epicentre.
- another term for focal point.
verb (focuses, focusing, focused or focusses, focussing, focussed)[no object]
mid 17th century (as a term in geometry and physics): from Latin, literally 'domestic hearth'
Some adverbials are used to focus attention on one part of a sentence:Paul regularly runs out of the nursery to play ball in a busy street; he has also run home by himself and was nearly hit by a lorry. The writer is adding to the dangerous things that Paul has done, and the adverb also helps focus our attention. If we remove the word, the sentence is much weaker:Paul regularly runs out of the nursery to play ball in a busy street; he has run home by himself and was nearly hit by a lorry. Other examples of sentences with focusing adverbials are:Utah, in particular, needs all the new employers it can find. Only the flowers in the vase on the table in front of me seemed real.
The different forms of the verb can be spelled with either a single or a double s: (focuses, focusing, focused or focusses, focussing, focussed).
The plural of the noun can be spelled either foci (as in the original Latin) or focuses.