prop. n. Bot. 'quick (lively) tree', Quickbeam. Tolkien notes that "_Quicken _or Quickbeam are actual names of 'rowan' or 'mountain-ash' = German Vogelbeere, Vogelbeerbaum.
Sindarin
bregalad
masculine name. Quickbeam; (lit.) Quick (Lively) Tree
Elements
Word Gloss bregol “quick, sudden, quick, sudden, [N.] violent, *fierce” galadh “tree”
Bregalad
noun. 'quick tree'
Name of an Ent, translated “Quickbeam” in The Lord of the Rings (LotR/482), but elsewhere said to more literally mean “Quick (Lively) Tree” (PE17/82, RC/762). His name is most likely a combination of bregol “sudden” and galadh “tree”, probably influenced by Nan. galad (assuming the name is not itself Nandorin).
Conceptual Development: His name already N. Bregalad when it first appeared in Lord of the Rings drafts from the 1940s, with the same meaning (TI/419, WR/26).