英和和英

connection

the state of being associated with something

to be related to

a close connection

the state of being connected

mutual relation―reciprocal relation―interrelation―reciprocity

to have a relation with someone or something

to sever relations―break off relations―sever connections―cut the connection―（between the two）

close in relationship

on a fair footing

to establish a relation to anything―establish a connection with anything

With that relationship

friendly relations―comradeship

relation to someone or something

a close relationship

on a friendly footing

to concern oneself with something

a relation between people

The relation is complicated.

a relationship

Deepen a relationship

a person who is involved and/or has a relation to something

interpersonal relations

of the relation between two {matters} or people, being slight

an alliance

meretricious relationships

mutually related

to form a friendly relationship

a cooperative relationship

something of that sort