'Loweringly' definitions:

Definition of 'loweringly'

(from WordNet)
adverb
In a menacing or scowling way; "he looked up loweringly"

Definition of 'Loweringly'

From: GCIDE
  • Loweringly \Low"er*ing*ly\, adv. In a lowering manner; with cloudiness or threatening gloom. [1913 Webster] lower limit