Learn French: Il mesure deux mètres et trois centimètres pour ce vêtement. - He measures two meters and three centimeters for this garment.

The verb mesurer can mean both to measure something and to be a certain height. Because of the phrase pour ce vêtement (for this garment), it means he is physically measuring out fabric. If you were talking about a person's height, Il mesure deux mètres would mean he is two meters tall.

Could I just say deux mètres trois instead of deux mètres et trois centimètres?

Yes, in everyday spoken French, it is very common to drop et and centimètres. However, including every word like in this sentence sounds much more precise, which makes sense for tailoring or sewing.

Should I pronounce the 's' at the end of mètres to connect it to the word et?

No. In French, you never make a liaison (a spoken connection) with the word et. The 's' in mètres remains completely silent.

I usually see 'clothes' translated as the plural les vêtements. Why is it singular here?

The singular un vêtement refers to a single piece of clothing or a specific garment. Since he is measuring fabric for one specific item, the sentence uses the singular ce vêtement instead of the plural ces vêtements (these clothes).