the.com/cub

means The young of a bear, lion, wolf, or similar carnivorous animal — also used loosely for an inexperienced young person, as in 'cub reporter.'

from From Middle English 'cub' or 'cubbe,' of uncertain origin — possibly related to an Old Norse or Scandinavian word for a stump or block, perhaps via a sense of something small and stubby, though etymologists aren't confident of the link. Some have floated a connection to Irish 'cuib' (dog), but this is considered doubtful. The honest answer is the trail goes cold a few centuries back — the word emerges in English without a clear parent, already meaning what it means now.