The Plural of Focus: Here’s What It Is and How to Use It

If you have ever second-guessed yourself on what the plural form of focus was and also wanted to learn more about the word, it’s grammar, it’s history, and plenty of examples of it used in a sentence, this article is practically made for you!

Your writing, at its best

Compose bold, clear, mistake-free, writing with Grammarly's AI-powered writing assistant

What Is the Definition of Focus?

According to Merriam-Webster’s English dictionary, the word focus has these definitions and uses. 

  • A center of activity, attraction, or attention; epicentre
    • The primary focus of the meeting was drug abuse
    • Put immigration into focus as a hot topic for commentators
  • A point of concentration
  • Directed attention
    • The focus is on helping the homeless 
    • A focus group on homelessness 
  • Direction
    • The team lost focus
  • A state or condition permitting clear perception or understanding
  • adjustment for distinct vision
  • also: the area that may be seen distinctly or resolved into a clear image
  • Focal Length
  • a point at which rays (as of light, heat, or sound) converge or from which they diverge or appear to diverge; a convergence of light; ellipse
  • specifically: the point where the geometrical lines or their prolongations conforming to the rays diverging from or converging toward another point intersect and give rise to an image after reflection by a mirror or refraction by a lens or optical system
  • a point of convergence of a beam of particles (such as electrons)
  • : one of the fixed points that with the corresponding directrix defines a conic section
  • : a localized area of disease or the chief site of a generalized disease or infection
  • : the place of origin of an earthquake or moonquake
  • in focus
    • : having or giving the proper sharpness of outline due to good focusing
    • get the binoculars in focus
  • out of focus
    • not in focus
  • Focus – Verb
    • Transitive verb
      • to cause to be concentrated
        • focused their attention on the most urgent problems
      • to adjust the focus of (the eye, a lens, etc.)
        • focus the telescope
      •  to bring into focus
        • The results of that research were focused for classroom presentation.
      • to bring (something, such as light rays) to a focus: CONCENTRATE
    • intransitive verb
      • to concentrate attention or effort
      • focus on the most pressing needs
      • to adjust one’s eye or a camera to a particular range
      • Newborn babies cannot focus for several months.
      • to come to a focus: CONVERGE

What Is the Difference Between Focus and Foci?

The word focus comes from the Latin language. As it is with many Latin words used in American English today, there is more than one correct an acceptable plural form. The Latin way of making focus plural is foci whereas the American English way is focuses. The more commonly academically accepted word is foci, so for papers or homework, it would be the best idea to use that for the plural form of focus.

The History and Origin of the Word

You can trace the roots of the word to the Latin focus. It originally meant a hearth or fireplace. Later in New Latin, it took on the scientific meaning to focus rays of light by using a glass lens. The way they got from fireplace or hearth to focusing a lens of glass was because they noticed the glass lens (magnifying glass) was able to catch paper on fire when it concentrated the beam of light to a fine point. The descendants of the original Latin include focar (Spanish), fuoco (Italian), fokus (German), foco (Portuguese), and foc (Romanian).

Example Sentences of the Word in Context

Synonyms of Focus From a Thesaurus

  • Axis – a straight line about which a body or a geometric figure rotates or may be supposed to rotate 
  • Base – the starting point or line, foundation 
  • Center – the point around which a circle or sphere is described 
  • Core – a central and often foundational part usually distinct from the enveloping part by a difference in nature
  • Cynosure – the center of attraction or attention
  • Epicenter – the part of the earth’s surface directly above the focus of an earthquae
  • Eye – attention, notice, close observation, point of view, something central
  • Ground zero – the point directly above, below, or at which a nuclear explosion occurs, the center of origin of rapid, intense, or violent activity or change 
  • Heart – the central or innermost part
  • Hub – the central part of a circular object, the center of activity, the focal point 
  • Locus – a center of activity, attention, or concentration
  • Mecca – a place regarded as a center for a specified group, activity, or interest
  • Navel – the central point, a depression in the middle of the abdomen that marks the point of former attachment of the umbilical cord or yolk stalk
  • Nerve center – center, source of leadership, organization, control, or energy
  • Nexus – connection, link


Now you are no doubt an expert on using the correct plural form of the word focus and hopefully also took away a lot more about the word and how to use it in the English language.