ADJ

bottom, top
driving along in top gear
high, low
first, second, etc.
reverse

VERB + GEAR

engage, select
Engage first gear and move off
change, change into, move into, put/slam/slip sth into, shift (into), switch
It's difficult to steer and change gear at the same time. She put the car into first gear and drove off
(figurative)
The party organization is moving into top gear as the election approaches
move up, step up
(often figurative) Coming out of the final bend, the runner stepped up a gear to overtake the rest of the pack
crash, grind
He was crashing the gears because he was so nervous

GEAR + NOUN

change
She made a smooth gear change
lever, stick (also gearstick)

PREP

in (a/the) ~
driving along in third gear Some drivers leave the car in gear when parking on hills
out of ~
Leave the car out of gear

ADJ

camping, climbing, fishing, running, sports, swimming, walking
breathing
firemen in breathing gear
landing, winding
the plane's landing gear
combat, riot
outdoor
designer
wearing expensive designer gear

VERB + GEAR

be dressed in, have on, wear
She had her running gear on
put on, take off

PREP

in … ~
a group of young men in combat gear