
1) Alarming 2) Baleful 3) Boding evil 4) Darkened by clouds 5) Daunting 6) Forbidding 7) Frightening 8) Gloomy 9) Ill-omened 10) Intimidating 11) Looming 12) Menacing 13) Minacious 14) Minatory 15) Nerve-racking 16) Ominous 17) Portentous 18) Scary 19) Sinister 20) Ugly 21) Unapproachable 22) Unpromising
Found on
https://www.crosswordclues.com/clue/threatening

1) Alarming 2) Cautionary 3) Dark 4) Dire 5) Lowering 6) Menacing 7) Minacious 8) Minatory 9) Minax 10) Sinister
Found on
https://www.crosswordclues.com/clue/threatening

• a. & n. from Threaten, v. • (p. pr. & vb. n.) of Threaten
Found on
http://thinkexist.com/dictionary/meaning/threatening/
Threat'en·ing adjective & noun from
Threaten ,
v. --
Threat'en*ing*ly ,
adverb Threatening letters (Law) ,
letters containing threats, especially those designed to extort money, or to obtain other property, by men...
Found on http://www.encyclo.co.uk/webster/T/49
No exact match found.