Adjectives ending with the letter W are listed in this post.
brand-new, bran-new, braw
callow, cash-flow, chow, chowchow, common-law
fallow, farrow, fellow, few, fire-new, fresh-new, frow
hebrew, highbrow, hollow
narrow, new, now
pay-per-view, peachblow, prow
sallow, seesaw, shallow, shrew, siddow, skew, slow, southpaw, span-new
Hope this word list had the adjective that ends in W you were looking for. Additional descriptive words can be found in the other pages on this site.