1 matter /ˈmætɚ/ noun
plural matters
1 matter
plural matters
Learner's definition of MATTER
[count] : something that is being done, talked about, or thought about
often used in an ironic way to refer to a difficult or important situation or problem
matters [plural] : the situation or subject that is being discussed or dealt with
physics : the thing that forms physical objects and occupies space
: material of a particular kind
see also back matter, front matter, gray matter, subject matter
the matter used to ask if there is a problem or to say that there is or is not a problem
often + with
Usage The question “What's the matter?” is usually asked in a friendly way. The question “What's the matter with you?” is usually asked in an unfriendly way by someone who is annoyed or angry.

a matter of

used to refer to a small amount
used to say that one thing results from or requires another
used to explain the reason for something
used to say that something is based on opinion, taste, etc.
used to say that something is important, interesting, etc.

a matter of debate

see 1debate

a matter of life and death

see 1life

a matter of record

: something that is known because it has been publicly said or reported in the past

as a matter of course

used to say that something will or should happen because it is natural, usual, or logical

as a matter of fact

see fact

for that matter

used with a statement that adds to a previous statement

mind over matter

see 1mind

no matter

informal used to say that something is not important
used with what, how, when, etc., to say that something does not, will not, or should not affect something else
see also no matter how you slice it at 2slice

the fact of the matter is

used to emphasize a statement that follows

the truth of the matter

used to stress the truth of a statement
2 matter /ˈmætɚ/ verb
matters; mattered; mattering
2 matter
matters; mattered; mattering
Learner's definition of MATTER
not used in progressive tenses [no object]
: to be important
often + that
often + how, who, what, etc.