reference

1 reference /ˈrɛfrəns/ noun
plural references
1 reference
/ˈrɛfrəns/
noun
plural references
Britannica Dictionary definition of REFERENCE
1 
: the act of mentioning something in speech or in writing : the act of referring to something or someone
[count]
[noncount]
— see also frame of reference, point of reference
2 
[noncount] : the act of looking at or in something for information
— see also cross-reference
3 
a  [count] : a person who can be asked for information about another person's character, abilities, etc.
— called also (British) referee
b  : a statement about someone's character, abilities, etc.
[count]
[noncount]
4 
[count] : something (such as a book, dictionary, encyclopedia, etc.) that people can look at or in to find information about something

in reference to

formal or with reference to
: about or concerning (something or someone) : in relation to

terms of reference

— see 1term
2 reference /ˈrɛfrəns/ verb
references; referenced; referencing
2 reference
/ˈrɛfrəns/
verb
references; referenced; referencing
Britannica Dictionary definition of REFERENCE
[+ object]
: to mention (something or someone) in speech or in writing : to refer to (something or someone)
3 reference /ˈrɛfrəns/ adjective
3 reference
/ˈrɛfrəns/
adjective
Britannica Dictionary definition of REFERENCE
always used before a noun
1 
: used to find information about something
2 
: used to tell people where information can be found