O contador de eletricidade tem um visor digital.

Here contador means meter or counter, not accountant. The full expression contador de eletricidade is the normal way to say electricity meter in European Portuguese.

For accountant, modern European Portuguese usually uses contabilista. So contador is a word where context matters a lot.

Portuguese often uses noun + de + noun to show what something is for or what type it is. So contador de eletricidade literally means meter of electricity, which is the standard way to name the device.

Using elétrico would not sound natural here. contador elétrico could suggest a counter that is electric, not specifically an electricity meter.

Da eletricidade is different: it sounds more like of the electricity in a specific context. For the general name of the object, de eletricidade is the normal choice.

In current standard spelling, eletricidade is correct. The older spelling electricidade may still appear, especially in older texts or signs.

The adjective elétrico keeps the accent because the stress falls earlier in the word: e-LÉ-tri-co. In eletricidade, the stress falls later: e-le-tri-ci-DA-de, so there is no written accent there.

Tem is the 3rd person singular present of the verb ter, which means to have. So here it means has.

Because the subject is o contador de eletricidade — a singular thing — Portuguese uses tem. If the subject were plural, you would use têm: Os contadores têm...

In Portuguese, adjectives often come after the noun. So visor digital is the normal, neutral order.

Putting the adjective before the noun is possible in some cases, but it is much less common and often changes the tone or emphasis. In this sentence, visor digital is exactly what a native speaker would expect.

Visor here means something like display, readout, or viewing window. It is a very natural word for the part of a meter where you see the numbers.

In Portugal, the general word for screen is often ecrã. But for a utility meter or a small device display, visor is usually the better fit.

This is the difference between the definite and indefinite article.

• o contador = the meter, a specific meter
• um visor digital = a digital display, introducing it as one feature of that meter

So the sentence treats the meter as something already identified, while the display is being mentioned as one of its characteristics.

• contador is masculine
• eletricidade is feminine
• visor is masculine

That is why you have o contador and um visor.

The adjective digital agrees in number, but in the singular it has the same form for masculine and feminine:

• um visor digital
• uma balança digital

In the plural, it becomes digitais.

People would probably understand you, but in European Portuguese, contador de eletricidade is the more natural and idiomatic choice.

In everyday speech, people also often say contador da luz. If you are learning Portuguese from Portugal, contador de eletricidade is the safest standard expression to learn.

Not normally as a neutral standalone sentence. Portuguese can drop subject pronouns, but not usually a full noun subject like o contador de eletricidade unless the context already makes it completely clear.

So if you are simply describing the object, O contador de eletricidade tem um visor digital is the natural full sentence. Tem um visor digital would sound conversational and dependent on previous context.