Meaning of SINGULAR in English

SINGULAR

I. sin ‧ gu ‧ lar 1 /ˈsɪŋɡjələ, ˈsɪŋɡjʊlə $ -ər/ BrE AmE adjective

[ Word Family: noun : ↑ single , singles, ↑ singleness , the singular, ↑ singularity ; adverb : ↑ singly , ↑ singularly ; adjective : ↑ single , ↑ singular ]

[ Date: 1300-1400 ; Language: Old French ; Origin: singuler , from Latin singularis , from singulus ; ⇨ ↑ single 1 ]

1 . a singular noun, verb, form etc is used when writing or speaking about one person or thing ⇨ plural :

the singular form of the noun

If the subject is singular, use a singular verb.

2 . [usually before noun] formal very great or very noticeable:

He showed a singular lack of tact in the way he handled the situation.

a singular achievement

3 . literary very unusual or strange:

I wondered why she was behaving in so singular a fashion.

II. singular 2 BrE AmE noun

the singular the form of a word used when writing or speaking about one person or thing ⇨ plural :

‘Datum’ is the singular of ‘data’.

in the singular

Should the verb be in the singular or the plural?

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.