excellent, good, nice
We need to achieve the best fit between the staff required and the staff available.

correct, exact, ideal, perfect, proper, right
bad, poor
The door was a poor fit and didn't open properly.

close, snug, tight
loose
comfortable
The sweater is a comfortable fit—not too tight and not too loose.

natural
custom (esp. AmE)
The cap is made of 92% polyester with 8% Spandex for a custom fit.

achieve, get, produce
File away any excess metal until a snug fit is achieved.

ensure
The shoe has a special strap to ensure a good fit.

fit between
a good fit between the recruit and the job

a lack of fit
He argues that there is a lack of fit between our system of values and capitalism.

convulsive, epileptic, fainting

have, suffer
She suffered a major fit last year.

suffer from
He suffers from fits of depression.

bring on, cause, trigger
He suffers from a brain disorder that can trigger convulsive fits.

control
new drugs that can control fits

prevent

happen, occur
The fits usually occur at night.

during a fit
She hurt her arm during one of her fits.

coughing, sneezing
crying, giggling, laughing, screaming
hysterical
sudden
In a sudden fit of anger, he snatched the book from her hand.

uncontrollable
He burst into an uncontrollable fit of laughter.

major

have, pitch (AmE), throw
My dad will throw a major fit if he finds out!

burst into, collapse in, collapse into, erupt in, erupt into, fall into
She collapsed in a fit of laughter.

bring on
The cold air brought on one of his coughing fits.

be over, pass
When her coughing fit was over she continued to speak.

in a fit of
He pushed the referee in a fit of temper.

fit of
a fit of anger/giggles

in fits (BrE), in fits of laughter
The comedian had them all in fits of laughter.

closely, neatly, nicely, securely, snugly, tightly, well
The pencils fit neatly into this box.

loosely
exactly, perfectly
The screws fit the holes exactly.

properly
The shoes don't fit properly.

badly, poorly
If the top of the box fits badly, the contents will spill out.

barely, hardly
jeans which barely fit his stout body

easily
That chair should fit into the room easily.

comfortably
PDAs are designed to fit comfortably in a jacket pocket.

together
These two pieces of wood fit together to make the base.

be designed to
The waste unit is designed to fit under the sink.

in, into, onto, over, under, etc.
Will this box fit into the cupboard?

perfectly
seamlessly
The haunting melody fits seamlessly within the song.

for (esp. BrE)
Your experience fits you perfectly for the job.

with
The words fit perfectly with the music.

Fit is used with these nouns as the subject:
analogy, description, shoe, size

Fit is used with these nouns as the object:
alarm, arrow, budget, carpet, category, criterion, data, definition, description, engine, expectation, heating, image, lifestyle, lock, meter, model, mould, need, niche, panel, part, personality, plug, preconception, preference, profile, rail, requirement, role, situation, stereotype, strap, tile, tyre, valve, windscreen

be, feel, look, seem
become, get
the struggle to get fit and stay fit

keep, stay
Go for a little jog to keep fit.

make sb
Exercising once a week is not enough to make you fit.

keep sb
gentle exercises designed to keep you fit

extremely, fairly, very, etc.
fighting (esp. BrE)
He seemed fighting fit and ready for action.

fully (BrE)
John isn't fully fit yet after his operation.

physically
She felt physically fitter and more alive than she could ever remember.

for (BrE)
The doctor said she was now fit for work.

as fit as a fiddle (= very healthy)
fit and healthy, fit and well (esp. BrE)
She looks really fit and healthy.

fit and ready
lean and fit

consider sth, see, think
The newspaper did not see fit to publish my letter.
You must do as you think fit.

for
The food was not fit for human consumption.

fit and proper (law, esp. BrE)
circumstances in which someone is not considered a fit and proper person to run a bank

fit for a king
It was a meal fit for a king.

in no fit state
He's so angry he's in no fit state to see anyone.

Fit is used with these nouns:
body, state