alarming
adjective
- to give warning to, frighten
Wiktionary
Pronunciation: /əˈlɑːm.ɪŋ/ / /əˈlɑɹm.ɪŋ/
adj
- Causing apprehension, fear or alarm; frightening.
“Another stop at the 731-yard Sharpthorne Tunnel allowed the apprentices to see how a combination of water and a "chemical soup" is destroying the rails at an alarming rate.”
verb
- present participle and gerund of alarm