alarming

• (UK) IPA^(key): /əˈlɑːm.ɪŋ/
• (US) IPA^(key): /əˈlɑɹm.ɪŋ/

alarming

1. present participle and gerund of alarm

alarming (comparative more alarming, superlative most alarming)

1. Causing apprehension, fear or alarm; frightening.
   • 2024 March 20, Richard Foster, “Vital experience in an open-air classroom”, in RAIL, number 1005, page 60:

     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.

• concerning, distressful, distressing, troubling, worrisome, worrying

• marginal