Meaning of “form” - Learner’s Dictionary

form

verb uk us /fɔːm/
BEGIN [ I, T ]

B2 to begin to exist, or to make something begin to exist:

[ often passive ] We are learning more about how stars are formed.
The trees form new leaves once the weather improves.
SHAPE [ I, T ]

to take or to make something take a particular shape:

Hold hands and form a circle.
Form the dough into little balls.
COMBINE [ T ]

B1 to make something by combining different parts:

In English you form the present participle by adding -ing to the verb.
START [ T ]

B2 to start an organization or business:

Brown formed her own company eleven years ago.
BE [ T ]

to be the thing talked about or be part of it:

The Alps form a natural barrier between Italy and Switzerland.
Her diary forms the basis of the book.
form an opinion/impression, etc

to begin to have a particular opinion or idea about something because of the information you have

(Definition of “form verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)