avid, close, considerable, consuming, deep, great, intense, keen, lively, passionate, real, strong
The police were starting to take a close interest in the company's activities.
She always had a great interest in the supernatural.

particular, special
growing, increased, increasing
slightest
He's never shown the slightest interest in football.

little
general, widespread
current
worldwide
shared
serious
genuine
abiding, lifelong, long-standing
passing
sudden
Why the sudden interest?

renewed
added
The CD-ROM gives the book added interest.

active
polite
He showed a polite interest in her story.

personal
professional
media
The event attracted a lot of media interest.

sexual

have
evince, express, show, take
My cousin expressed an interest in seeing where I work.

feign
She feigned interest in a magazine article to avoid meeting the man's stare.

lose
arouse, attract, awaken, catch, create, draw, drum up, excite, generate, kindle, pique, spark, stimulate, stir up
A sticker on a bag caught my interest.
The government failed to drum up any public interest in the referendum.
A childhood trip to Europe sparked his lifelong interest in history.

develop
While in prison he developed an interest in art.

increase
keep, maintain, sustain
The film kept my interest throughout.
The channel has failed to maintain interest in its expensive new show.

revive

grow
flag, wane
The children's interest began to flag after half an hour of the lesson.

for interest, out of interest
I'm asking purely out of interest.

with interest
They listened with interest.

interest among
to stimulate interest among teachers

interest from
growing interest from younger members

interest in
She took an active interest in their welfare.

great
particular, special
Her comments are of particular interest to me.

little
immediate
This information was of no immediate interest to me.

broad, general, wide
architectural, artistic, historic, historical, scientific
academic
Since the championship has already been decided, this game is of purely academic interest.

human
a plot devoid of human interest

love
Angelina Jolie supplies the love interest in the movie.

be of
His books are of no interest to me at all.

hold no
Their conversation held no interest for me.

add
Bushes that flower in winter will add interest to your garden.

lie in
The interest of the painting lies in its unusual use of light.

of interest
a building of great architectural interest

diverse, varied, wide, wide-ranging
private
shared
outside
He has many hobbies and outside interests.

main, primary
My main research interest is herbal medicine.

artistic, musical, etc.
research

have
share
pursue
He wanted time to pursue his many and varied musical interests.

annual, monthly, etc.
compound, simple
mortgage

earn, receive
pay
charge

accrue, bear

rate
payment
charge

interest on
to pay interest on a loan

a rate of interest
a mortgage with a fixed rate of interest

best interest (esp. AmE), best interests
It's not in your best interests to let your boss know you're looking for a new job.
I feel it is in everyone's best interest if I step aside now.

own, selfish
You can't blame them for looking after their own interests. (esp. BrE)

common, mutual, shared
competing, conflicting, contradictory
long-term, short-term
narrow
Protectionism often simply supports narrow vested interests.

direct
Lawyers have a direct financial interest in the outcome of the debate.

paramount, vital
powerful
legitimate
vested
special (esp. AmE)
The views of special-interest groups are represented.

national, public
class, sectarian, sectional
foreign, outside
corporate, economic, financial, political, security, strategic, etc.
issues of compelling strategic interest

defend, guard, look after (esp. BrE), protect, safeguard
act in, advance, champion, further, promote, serve
He claimed to be acting in the public interest.
This policy serves the interests of the United States.

represent
act against, jeopardize, threaten

lie in sth
be at stake

group
Various interest groups have expressed their opposition to the policy.

against sb/sth's interest
The lawyer refused to act against his client's interests.

contrary to sb/sth's interest
The union refused to support proposals that it saw as contrary to the interests of its members.

in sb/sth's interest (esp. AmE), in sb/sth's interests (esp. BrE)
Continuing such a policy is short-sighted and not in the interest of consumers.
New work practices were introduced in the interests of efficiency.

of interest
We met to discuss matters of common interest.

out of interest
He was obviously acting purely out of selfish interest.

a conflict of interest, a conflict of interests (esp. BrE)
One member of the planning committee had a conflict of interest as he lived near the proposed road.

have sb's interests at heart
Although he was sometimes too strict with his children, he had their best interests at heart.

powerful
controlling, majority
minority
joint
banking, business, commercial, shipping

have
He has controlling interests in several ventures.

sell

interest in