ADJ

dire, terrible
Despite dire threats of violence from extremist groups, the protest passed off peacefully
empty, idle
The kids took no notice of the teacher's idle threats
implied, veiled
The company's pay offer was accompanied by thinly-veiled threats of redundancies if it was rejected
explicit
physical, violent
verbal
bomb, death, suicide

VERB + THREAT

issue, make, utter
receive
carry out
It's unwise to make threats that you cannot carry out
lift, withdraw
Teachers have lifted their threat of strike action
reduce
give in to
The government refused to give in to the hijackers' threats

PREP

~ against
The accused made death threats against a notable politician

ADJ

big, considerable, dangerous, deadly, grave, great, major, real, serious, significant
main
growing, increasing
constant, continual, continuous, ever-present, permanent
renewed
The national park is under renewed threat from road-building schemes
direct, immediate, imminent
The opposition presents no immediate threat to the government
insidious
long-term, short-term
potential
apparent, perceived
external
The government was faced with internal rebellion as well as external threats
physical
political
environmental
military, nuclear, terrorist

VERB + THREAT

be, pose, present, represent
the environmental threat posed by oil spillages
consider sth (as), perceive sth as, regard sth as, see sth as, view sth as
Translators do not yet perceive computers as a threat to their livelihood
face, meet

PREP

under ~
Many wild plants are under threat of extinction
~ from
the threat from overfishing
~ of
a threat of violence
~ to
The junta reacted violently to the perceived threat to its authority