ADJ

engagement, eternity, signet, wedding
diamond, gold, etc.
She wore a diamond engagement ring

VERB + RING

have on, wear
He had a signet ring on his little finger
put on
take off

RING + NOUN

finger (= the finger next to the little finger, especially on the left hand)

ADJ

inner
outer
concentric
The street plan of the city has evolved as a series of concentric rings
black, dark
He had dark rings around his eyes
smoke, tree
to blow smoke rings

VERB + RING

form, stand in
The children formed a ring around their teacher

PREP

in a/the ~
The children sat on the floor in a ring

ADJ

boxing, bull, circus, show, wrestling

PREP

in/into the ~
He was back in the ring (= the boxing ring) only a month after the injury

PHRASES

retire from the ring (= stop boxing)

ADJ

drugs, smuggling, spy

VERB + RING

be involved in
break up
Customs officials have broken up a major drugs ring

VERB + RING

give sb
I'll give you a ring once I get home