Meaning of DOT in English

I. dot 1 S2 /dɒt $ dɑːt/ BrE AmE noun [countable]

[ Language: Old English ; Origin: dott 'top of a spot on the skin' ]

1 . a small round mark or spot:

a pattern of dots

2 . on the dot informal exactly on time or at a particular time:

I’ll be there on the dot.

at three o'clock/seven thirty etc on the dot (=at exactly 3:00/7:30 etc)

Mr Green arrived at six on the dot.

3 . something that looks like a small spot because it is so far away:

The plane was just a dot on the horizon.

4 . a short sound or flash of light used when sending messages by ↑ Morse code ⇨ dash

⇨ the year dot at ↑ year (13)

II. dot 2 BrE AmE verb ( past tense and past participle dotted , present participle dotting ) [transitive]

1 . to mark something by putting a dot on it or above it:

She never dots her i’s.

2 . [usually passive] if an area is dotted with things, there are a lot of them there but they are spread far apart

be dotted with something

The lake was dotted with sailboats.

be dotted about/around etc something

The company has over 20 stores dotted around the country.

Poppies dotted the field.

3 . to put a very small amount of something on a surface, especially in several places

dot something with something

Dot the apples with butter.

4 . dot the i’s and cross the t’s informal to pay careful attention to all the details when you are finishing something

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